Road Safety Fundamentals

Concepts, Strategies, and Practices that Reduce Fatalities and Injuries on the Road Notice This document is disseminated under the sponsorship of the U.S. Department of Transportation (USDOT) in the interest of information exchange. The U.S. Government assumes no liability for the use of the information contained in this document. The U.S. Government does not endorse products or manufacturers. Trademarks or manufacturers’ names appear in this report only because they are considered essential to the objective of the document.

Quality Assurance Statement The Federal Highway Administration (FHWA) provides high-quality information to serve Government, industry, and the public in a manner that promotes public understanding. Standards and policies are used to ensure and maximize the quality, objectivity, utility, and integrity of its information. FHWA periodically reviews quality issues and adjusts its programs and processes to ensure continuous quality improvement.

This document can be downloaded for free in full or by individual unit at: https://rspcb.safety.fhwa.dot.gov/rsf/ 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA-SA-18-003 4. Title and Subtitle 5. Report Date Road Safety Fundamentals: November 2017 Concepts, Strategies, and Practices that Reduce Fatalities and Injuries on the Road

7. Author(s) 6. Performing Organization Code Lead Editor: Daniel Carter, P.E., Senior Research Associate Unit Authors: 8. Performing Organization Report No. Unit 1: Dan Gelinne, Program Coordinator, UNC Highway Safety Research Center Unit 2: Bevan Kirley, Research Associate, UNC Highway Safety Research 9. Performing Organization Name Center and Address Unit 3: Carl Sundstrom, P.E., Research Associate, UNC Highway Safety University of North Carolina, Research Center Highway Safety Research Center Unit 4: Raghavan Srinivasan, Ph.D., Senior Transportation Research Engineer; Daniel Carter 10. Work No. (TRAIS) Unit 5: Daniel Carter; Jennifer Palcher-Silliman, Communications Manager, UNC Highway Safety Research Center

Layout and Graphics: Graham Russell, Graphic Designer, UNC Highway 11. Contract or Grant No. Safety Research Center Technical Editors: Jennifer Palcher-Silliman; Patty Harrison, 13. Type of Report and Period Covered Communications Specialist, UNC Highway Safety Research Center; Text book Caroline Mozingo, Senior Manager of Communications, Education and Outreach, UNC Highway Safety Research Center

12. Sponsoring Agency Name and Address 14. Sponsoring Agency Code Federal Highway Administration Office of Safety 1200 New Jersey Ave., SE Washington, DC 20590 15. Supplementary Notes The project manager for the textbook was Felix H. Delgado, P.E., FHWA Office of Safety

16. Abstract This book provides an introduction to the fundamental concepts of road safety. The book’s goal is to equip the reader with a broad base of knowledge about road safety. Thus, the focus is in communicating concepts rather than providing instruction in detailed analysis procedures.

The audience for this book is two-fold. First, this is intended for those whose job addresses some aspect of road safety, particularly in a public agency setting. Second, this book is intended for professors and students in a university setting.

This book seeks to lay the foundation of road safety knowledge regardless of a particular discipline. Professionals with a background in engineering, planning, public health, law enforcement, and other disciplines will benefit from the concepts presented here. 17. Key Words 18. Distribution Statement road safety, road safety management process, site-level management, system No restrictions level management, human behavior, safety performance measures, road safety data, multidisciplinary approaches 19. Security Classif. 20. Security Classif. 21. No. of Pages 22. Price (of this report) (of this report) 188 FREE Unclassified Unclassified

Form DOT F 1700.7 (8-72) Reproduction of completed pages authorized

TABLE OF CONTENTS

UNIT 1 Foundations of Road Safety Chapter 1: Context of Road Safety Chapter 2: Road Safety Through the Years Chapter 3: Multidisciplinary Approaches Chapter 4: Road Users

UNIT 2 Human Behavior and Road Safety Chapter 5: Understanding Human Behavior Chapter 6: Changing Human Behavior

UNIT 3 Measuring Safety Chapter 7: Importance of Safety Data Chapter 8: Types of Safety Data Chapter 9: Improving Safety Data Quality

UNIT 4 Solving Safety Problems Chapter 10: Road Safety Management Process Chapter 11: Site-Level Safety Management Chapter 12: System-Level Safety Management

UNIT 5 Implementing Road Safety Efforts Chapter 13: Who Does What Chapter 14: Road Safety Research Chapter 15: Strategic Communications Chapter 16: Advancing Road Safety

ROAD SAFETY FUNDAMENTALS 1 INTRODUCTION

This book provides an introduction to many of the fundamental concepts of road safety. These concepts cover areas such as the nature of road safety issues, human behavior in the road environment, and identifying and solving road safety problems. The goal of this book is to equip the reader with a broad base of knowledge about road safety. Thus, the focus of the text is in communicating concepts rather than providing instruction in detailed analysis procedures.

The audience for this book is two-fold. First, this is intended for those whose job addresses some aspect of road safety, particularly in a public agency setting. This is especially relevant for individuals who have been tasked with managing road safety but who do not have formal training in road safety management. In order to show practical applications of each road safety concept, this book contains many examples that demonstrate the concepts in real-world settings. Second, this book is intended for professors and students in a university setting who can use individual units or this entire book to add an emphasis on road safety as part of graduate- level work. Each unit provides learning objectives and sample exercises to assist professors as they incorporate content into their courses.

As a final note, this book is intended to lay the foundation of road safety knowledge regardless of a particular discipline. Professionals with a background in engineering, planning, public health, law enforcement, and other disciplines will benefit from the concepts presented here.

2 ROAD SAFETY FUNDAMENTALS ABOUT THIS BOOK

This book is divided into five units according to major topics of road safety knowledge. Each unit is divided into multiple chapters that address the primary concepts of the unit. The beginning of each unit provides a list of learning objectives that indicate what the reader will be able to understand, describe, identify, or otherwise do by the end of the unit.

Each chapter presents call-out boxes, glossary definitions, and references as shown below.

Secretary Hoover called a second to coordinate crash research conference for March 1926. During nationwide. The HRB played a major Uniform A the interim between the two part in subsequent efforts to reduce Vehicle Code B Call-out conferences, a special committee the consequences of crashes.8 A code covering Glossary drew up a model “Uniform Vehicle registration and boxes are titling of vehicles, definitions are Code” covering registration and Federal Government Role B titling of vehicles, licensing of in Highway Development licensing of provided drivers, and provided along drivers, and operation of vehicles on operation of The growing use of motor vehicles throughout the the highways. The code incorporated vehicles on the side of the the best features of the numerous during the 1920s was mirrored the highways. book to provide and varied State laws then on by the expansion of the Federal page. These the statute books. The second Government’s role in funding and examples conference approved this code building roads. In its early form, the 8 correspond to and recommended it to the State Office of Public Roads was organized of concepts Source: America’s words in bold legislatures as the basis for uniform under the U.S. Department of Highways, 1776-1976: presented in motor vehicle legislation. Agriculture, playing a large role in A History of the face in the page funding roadways within national Federal-Aid Program. Studies following this 1926 Federal Highway the chapter. parks and forests. Administration C content. conference concluded that (U.S. Government determining the causes of crashes Following the Federal Aid Road Act Printing Office, Washington D.C., was far more difficult than they had of 1916, this office would become 1976). presumed. The problem warranted the Bureau of Public Roads (BPR), a sustained program of research charged with working cooperatively by a national organization. The with State highway departments on C Conference agreed, and the Highway road projects. Work continued on References Research Board (HRB) organized the expansion of highways across the Committee on Causes and the country, and between 1921 and to source Prevention of Highway Accidents 1939, the distance of paved roads material are

Balanced Design for Safety provided along In the 1920s and 1930s, it was good Increasing concern for road safety led many the side of the engineering practice to design new highway engineers to worry about this A highways as much as possible in long inconsistency between posted speed limits page. These straight lines or “tangents.” When it and safe design speed on curves. In 1935, became necessary to change direction, highway engineer Joseph Barnett of the BPR are numbered the engineer laid out a circular curve, proposed that all new rural roads conform to the radius of which he selected to fit an “assumed design speed,” a comfortable consecutively the ground with the least construction top speed for drivers outside of urban areas. cost, but which could not be less than a With its adoption by American Association through the unit certain minimum fixed by department of State Highway Officials in 1938, Barnett’s policy. In practice, engineers made the “balanced design” concept became a and correspond curves sharper than this minimum when permanent feature of U.S. roadway design. it was cheaper to do so, but with little Today, standards for designing curves, to numbers consistency. Engineers expected motorists such as design speed, curve radius and driving these roads to adjust their speeds superelevation (the tilt of the road through in the page to the varying radii, and on the sharper a curve) are provided in A Policy on curves safe design speed might be Geometric Design of Highways and Streets, content. considerably lower than the posted produced by the American Association for speed limit. State Highway Transportation Officials.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-13

ROAD SAFETY FUNDAMENTALS 3 UNIT 1 Foundations of Road Safety

LEARNING OBJECTIVES

After reading the chapters and completing JJ DISTINGUISH between nominal exercises in Unit 1, the reader will be able to: and substantive safety

JJ DESCRIBE the importance of road JJ IDENTIFY key points in the history of safety and how it relates to public road safety in the U.S., including key health, economic, environmental legislation and agency formation, and and demographic trends understand how these decisions have shaped today’s roadways JJ RECOGNIZE roles and responsibilities of various disciplines and approaches JJ IDENTIFY different groups of road users to improving road safety and challenges unique to each group

1-b UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS CHAPTER 1 FOUNDATIONS OF ROAD SAFETY Context of Road Safety

Road safety is an important part of everyday life. Across the nation, people use roads and sidewalks to get to work, school, stores, and home. Public agencies work to ensure that people arrive at their destination without incident.

However, not every trip is without incident. Deaths and injuries resulting from motor vehicle crashes represent a significant public health concern. The World Health Organization (WHO) estimates that motor vehicle crashes kill more than 1 million people around the world each b year, and seriously injure as many as 20 to 50 million.1 These crashes affect 1 all road users, from vehicle drivers FIGURE 1-2: Traffic Fatalities in the U.S. by and passengers to pedestrians, Person Type, 2013 (Source: NHTSA FARS) http://www.who.int/ bicyclists, and transit users. features/factfiles/ roadsafety/en Though road safety in the U.S. has steadily improved over people were killed each year and time, it remains a priority for an estimated 2.3 million were transportation agencies, legislators, injured in motor vehicle crashes.2 and advocacy organizations. Over While many of these deaths and 2 the past 10 years in the U.S., an injuries are sustained by motor National Highway average of approximately 37,000 vehicle passengers and drivers, Traffic Safety Administration (NHTSA). Fatality 50000 Analysis Reporting System (FARS). 40000 http://www.nhtsa. gov/FARS 30000

20000

10000 1983 1988 1993 1998 2003 2008 2013

FIGURE 1-1: Traffic Fatalities in the U.S. by Year, 1983-2013 (Source: NHTSA FARS)

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-1 3500 6 b 3000 5 100 4 2000 3

2 1000 1 1966 1976 1986 1996 2006

FIGURE 1-3: Fatality Rate and Vehicle Miles Traveled, 1966-2013 (Source: NHTSA FARS)

they also impact motorcyclists, more complex due to the multitude pedestrians, bicyclists, and users of factors influencing safety, from of transit vehicles. This challenge infrastructure to vehicle design to requires a comprehensive approach human behavior. Crash to improving safety, involving Road safety professionals typically frequency numerous stakeholders and measure safety by the number and decision makers from a variety of The number perspectives and disciplines. rate of crashes and by the severity of crashes of those crashes. Crash frequency, or occurring per the number of crashes occurring per year or other Defining Safety unit of time. year or other unit of time, is another In the simplest terms, safety can commonly used metric. Crash rates be defined as the absence of risk are numbers of crashes normalized or danger. Focusing this term to by a particular population or metric Crash rate address transportation, road safety of exposure. Commonly cited crash can be characterized by the ability The number rates include crashes per 100,000 of a person to travel freely without of crashes people living in a particular State, normalized by injury or death. A perfectly safe city or country. Some crash rates a particular transportation system would not present crash numbers per miles population experience crashes between various traveled or licensed drivers. Crash or metric of road users. Though absence of all outcomes can be measured by exposure. crashes is an optimal condition, and the types of injuries sustained to many transportation agencies have the people involved in the crash, a goal of zero deaths on the road, typically categorized by fatalities Crash the reality is that people continue and injury severity. Focusing on to get injured or killed on streets outcome crashes that result in severe injuries and highways across the nation. The Measured and fatalities is one strategy that challenge posed to the road safety by the types agencies use to prioritize their field is to minimize the frequency of injuries safety activities. sustained to the of crashes and the resulting deaths people involved and injuries using all currently In addition to the measures in the crash. available tools, knowledge, and described above, safety professionals technology. This challenge is made can use surrogate measures, such as

1-2 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS conflicts (near misses), avoidance can use surveys, driving simulators, maneuvers, and the time to collision and other modern technologies to if no evasive action is taken, to understand the safety perception of determine the level of safety risk road users. and identify specific problems. Evaluating the safety of a particular Safety problems may exist even network, corridor or intersection in locations that do not have a requires an understanding of both demonstrated history of crashes, just as someone who smokes is at nominal and substantive safety. higher risk for lung cancer even if Originally introduced by Dr. Ezra 3 no cancer has yet been detected. Hauer, these terms offer a helpful 3 This can be especially true for framework for assessing the safety of a particular location. Decades of Hauer, E. non-motorized road user safety, Observational such as pedestrians and bicyclists, research and evaluation in the field Before/After Studies since crashes involving these of road safety have revealed a wealth in Road Safety. of knowledge concerning the proper Estimating the Effect road users may be infrequent and of Highway and appear random at first sight. In designs and policies that contribute Traffic Engineering to the safety of a particular location. Measures on Road such locations where crashes are Safety. Pergamon sparse or distributed across the Roadways constructed according to Press. 1997. system, safety professionals can use the best and latest recommended surrogate measures to fill the gaps research and design standards are and assess the road’s level of risk. said to be nominally safe. Nominal safety is an absolute statement Nominal Observing traffic at an intersection, safety for example, may reveal a pattern about the safety of a location based of near misses and other conflicts only on its adherence to a particular An absolute between vehicles and pedestrians. set of design standards and related statement about the safety This pattern may not appear in criteria. A road that was nominally of a location safe when it was first opened to crash data, but can be a valuable based only on source of information to highlight traffic may become nominally its adherence the potential for safety risk. unsafe when the roadway design to a particular standards change, even though set of design Safety perception is also an the road’s crash performance has standards and important consideration for travel not changed. related criteria. choices. There are a number of reasons why someone may or may While nominal safety considers not choose a particular route to the design of a road, it does not drive, walk or bike. Pedestrians who incorporate any information about perceive an intersection to be unsafe the frequency, type and severity of may cross in a midblock location, crashes occurring on the facility. The where they are more easily able to historical and long-term objective find a gap in traffic. Motorists may safety of a location based on crash Substantive feel uneasy about making a left turn data is known as substantive safety. safety across multiple lanes of traffic, so A particular intersection that has Historical and they may choose to turn right and experienced fewer than expected long-term travel out of their way to perform crashes over an extended period objective safety a U-turn instead. Safety perception will be referred to as a substantively of a location impacts road user decisions but is safe location, while a corridor with based on not easily understood by looking a higher than expected number of crash data. at crash data. Safety professionals crashes is substantively unsafe.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-3 Unlike nominal safety, substantive safety operates on a continuum and allows for a range of explanations as to why a particular safety problem exists.

Another key distinction is the fact

that a location can be nominally safe – adhering to all standards and design criteria – while experiencing high rates of crashes, making it substantively unsafe. Similarly, a substantively safe location (one that has a lower than expected crash FIGURE 1-4: Comparison of nominal rate) may be nominally unsafe if it and substantive concepts of safety http:// does not meet the applicable design safety.fhwa.dot.gov/geometric/pubs/miti- standards. gationstrategies/chapter1/1_comparnom- inal.cfm (Source: NCHRP Report 480, Agencies and safety professionals Transportation Research Board, 2002) should strive to prioritize the substantive safety of a facility. Simply building a road that meets all trade-offs – making a decision to the current design standards will not favor one goal at the expense of ensure that the road is substantively another. While those in the field of safe. Using professional judgement road safety continually look for to prioritize safety improvements new designs and technologies to and select appropriate designs advance all goals, there continue within a range of options, based on to be many instances where public observations of road user behavior agencies must weigh competing and other available data, will goals for a location or portion of increase the chance that all factors the road network and decide what are considered. The end result will trade-offs should be made for the be a road that moves a step closer goal of increasing road safety. to the ultimate goal of having a transportation system free of Below are several examples: injuries and deaths. JJ Roundabouts: A city may decide Road Safety Decisions to install a roundabout at an and Trade-offs intersection to decrease the potential conflicts between The goal of improving safety various movements at the exists alongside other goals of the intersection. Safety is improved, transportation system, such as especially related to left-turns, mobility, efficient movement of since all turns are now part of the people and goods, environmental circle. However, a roundabout concerns, public health, and does require traffic on the main economic goals. In this way, road to slow their speeds and transportation professionals and navigate through the roundabout. policy makers often refer to During heavy traffic, especially

1-4 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS if it is unbalanced among the records information about intersection legs, this may those who violate red light cause a decrease in the overall laws, typically resulting in throughput of the intersection. citations through the mail. These However, this is a trade-off to cameras have been shown to produce fewer crashes. improve safety by decreasing 4 JJ Bicycle Helmet Requirements: the types of crashes that result in serious injury,4 but installing Council, et al. In order to improve bicyclist Safety Evaluation of safety, some jurisdictions have the cameras can be met with Red-Light Cameras. adopted ordinances that require significant public opposition. Federal Highway Administration. bicyclists to wear helmets. In JJ Protected Left Turns: To April 2005. https:// practice, this can reduce the risk www.fhwa.dot. minimize the risk of severe gov/publications/ of head injuries among cyclists, left-turn crashes at signalized research/safety/ 05048/05048.pdf but it may also reduce the intersections, engineers may number of people who choose choose to provide left turning to ride a bicycle. Adopting such drivers an exclusive protected ordinances would prioritize left turn phase (green arrow). safety while potentially reducing While this minimizes crash risk bicycle ridership. by separating the left turning JJ Red Light Cameras: Red light vehicles from other movements, camera enforcement monitors it also requires that extra time signalized intersections and be added specifically for left

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-5 turns, which can increase delay too close to an intersection for the rest of the traffic at the can restrict sight distance, intersection. contributing to crashes. Selected tree and vegetation removal is an JJ Rumble Strips: In rural locations, excellent example of a rumble strips can be installed as trade-off between safety and a measure to alert drivers when other beneficial features of trees. they are running off the road. However, these rumble strips are JJ Traffic Signal Installation: A usually installed on the edge of high-speed, high-volume road the road or the paved shoulder with multiple traffic lanes may where bicyclists can safely and separate housing developments comfortably ride separated from an elementary school. In from traffic. This may result order for children living in the in bicyclists riding in the road housing development to safely where they are more vulnerable travel to and from school, a to crashes with motor vehicles. traffic signal and crosswalk may be installed along the busy road. JJ Trees and Landscaping: Motorists will be delayed since Street trees, shrubs, and they are required to stop for a other vegetation can serve a period of time while the students valuable purpose in roadside cross, but the crossing is safer environments – particularly for those students. creating shade for the sidewalk, serving as a buffer between the JJ Access Management: Left turns road and sidewalk area, and in and out of shopping centers, even creating “visual friction” especially along multilane roads, that can keep vehicle speeds can result in severe injuries to down. However, trees can also motorists when crashes occur. pose a safety risk for vehicles Eliminating these left turns by that run off the road and collide building raised median islands with them. Vegetation that is and consolidating driveways

1-6 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS can eliminate these risky movements; however, this prevents direct access to the stores by potential customers.

Sometimes improving safety for one group of road users may negatively impact the safety of another group. It can also be the case that improving mobility for a group of road users may negatively affect the safety of that same group. There is no absolutely correct answer to many of these trade-offs, as they are all context-specific. Transportation professionals need to discuss the various trade-offs in the context of a particular community’s transportation goals. These types of trade-offs are made every day, and about the transportation system, require the cooperation of numerous transportation professionals agencies and stakeholders, all must understand the impacts – of whom have a role to play in both positive and negative – that transportation decision-making. design, operations, and policy Despite the temptation to study road decisions have on the safety of safety as a self-contained system, the transportation network as there are a multitude of factors well as the impacts on other areas influencing and being influenced by such as public health, mobility, road safety and travel behavior. In environmental quality, and order to make informed decisions economic growth.

EXERCISES

JJ LIST various ways to measure the safety JJ DESCRIBE a change that could be made of a road and describe the advantages to a road or intersection that would and disadvantages of each. Consider fac- improve road safety at the expense of tors such as the type of information each another transportation goal (e.g., traffic safety measure provides as well as other operations, public health, mobility and issues such as how it can be collected. access, environmental quality, or eco- nomic growth). JJ DESCRIBE a change that could be made to a road or intersection that would JJ DESCRIBE a change that could be improve one transportation goal (e.g., made to a road or intersection that traffic operations, public health, mobili- would improve safety for a road user ty and access, environmental quality, or but not at the expense of other users, economic growth) at the expense of the or other goals. safety of road users.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-7 CHAPTER 2 FOUNDATIONS OF ROAD SAFETY Road Safety Through the Years

When examining current efforts to however, it is most useful to begin address road safety, it is useful to the discussion in the late nineteenth view them in the context of American century. transportation history. Recent In the 1880s and 1890s, bicycles decades have witnessed numerous were the dominant vehicle on advances in the field of road safety. This growing national consciousness our nation’s roads. With the about the need for safer roads introduction of the “safety” bicycle, provides a stark contrast to the first with two wheels of the same size, half of the twentieth century when and the pneumatic tire in the late the focus was on highway expansion. 1880s, the bicycling craze became an The following chapter will provide economic, political, and social force an overview of the major milestones in the U.S. By 1890, the U.S. was and achievements that led to the manufacturing more than 1 million transportation system we have today, bicycles each year. as well as the policies and practices At that time, bicyclist behavior— that were implemented to address a particularly careless or risk-taking growing safety problem. behavior—was a contributing Late Nineteenth Century and factor to bicycle crashes. However, the biggest contributor to crashes the Popularity of Bicycling existed outside the cities; the poor An exploration of the history of condition of the nation’s roads made road safety in the U.S. can begin at cycling a laborious and dangerous many different points – some of process. Bicycle groups worked our roads were developed as pre- at the Federal, State, and local colonial routes and others were levels to secure road improvement trails blazed by Native Americans. legislation. The work of these In terms of lasting influence on the advocacy groups became known as modern transportation network, the Good Roads Movement.

Three men with bicycles on bridge near Pierce Mill, Washington, D.C., 1885. (Source: Brady-Handy Collection, U.S. Library of Congress)

1-8 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS Consequences of Speeding As in modern times, in the early days of the These improvements along with mechanical automobile, posted speed limits were set advances in vehicles, such as more far below the speed of which most motor powerful engines and four-wheel brakes, vehicles were capable. in turn encouraged even faster speeds. With faster and heavier traffic, it became Thus, after 1918, highway design followed dangerous to drive in the middle of a spiral of cause and effect, resulting in the road and the States began painting faster and faster speeds and wider and centerlines on the pavements to channel wider pavements. The motivating force traffic in lanes. At 40 miles per hour, these behind this spiral was the driving speed lanes appeared uncomfortably narrow to preferences of the great mass of vehicle most motorists, especially when passing operators. The public authorities were trucks. The lane lines also caused trucks never able to impose or enforce speed to run closer to the shoulder, causing the limits for very long if the majority of drivers slab edges and corners of the road to considered the limits unreasonably low. break. To provide greater safety and Now, many current engineering practices 5 use the 85th percentile speed – or the reduce edge damage, State highway Source: Richard departments built wider pavements speed at which the majority of drivers travel F. Weingroff, “A and made new roads straighter. – as the method of setting speed limits. Peaceful Campaign of Progress and Reform: The Federal Highway To build support, advocates tailored later, 2.33 million automobiles were Administration at 100,” Public Roads their message to farmers with traveling the country’s roads, and by 57, no. 2 (Autumn, the argument that bad roads, 1918, this number had increased to 1993), http://www. by increasing transportation fhwa.dot.gov/ 5.55 million. Mass production made publications/ expenditures, cost more than good this increase possible as it lowered publicroads/93fall/ p93au1.cfm roads. While engineers, writers, and vehicle manufacturing costs, putting politicians joined the movement, vehicles within the reach of the bicyclists dominated the Good Roads middle class. As more vehicles Movement until cars arrived in the 6 5 became available at a lower price, early twentieth century. Soniak, Matt. When the pattern of daily travel in the U.S. and Where Was the By the close of century, automobiles began to shift. Longer vehicle trips First Car Accident? had slowly begun to share the roads Mental Floss. replaced shorter trips by foot or 2 December 2012. with bicyclists and pedestrians, bicycle, and development patterns http://mentalfloss. benefitting from many of the road began to follow suit. The motor age com/article/31807/ improvement efforts spearheaded when-and-where- had arrived, and with it a new kind was-first-car- by cycling groups. In 1899, a motor of highway would evolve, designed accident vehicle struck and killed a New specifically for motor vehicles. York City pedestrian. This event marked the first time in the U.S. Expansion of automobile use had 7 that a person was killed in a crash immediate positive effects on the Source: America’s 6 involving a motor vehicle. national economy and quality of life Highways, 1776-1976: A History of the Rise of Motor Vehicles in the around the country. Yet proliferation Federal-Aid Program. of motor vehicles also had a negative Federal Highway Early Twentieth Century Administration side. As millions of new drivers (U.S. Government In 1905, only 78,000 automobiles, took to the roads, traffic crashes Printing Office, Washington D.C., most of which were confined to the increased rapidly—tripling from 1976). cities, traveled the U.S. Ten years 10,723 in 1918 to 31,215 in 1929.7

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-9 Secretary of Commerce Herbert Hoover, center, with President Calvin Coolidge, right, in February 1924. (Source: Harris & Ewing Collection, U.S. Library of Congress)

Shifting Attention to Safety injury, and 38 required railroads and common carriers to report Recognizing the rise in crashes and highway crashes. Other committees resulting injuries and fatalities, devoted their attention to issues like Secretary of Commerce Herbert traffic control and vehicle speeds, Hoover convened the First infrastructure and maintenance National Conference on Street and concerns, and issues impacting Highway Safety in Washington, vehicles and their drivers. D.C., in December 1924. Here, for the first time, representatives of Conference participants supported State highway and motor vehicle a wide range of measures to commissions, law enforcement, reduce the rate of crashes and insurance companies, automobile recommended that legislative, associations and a multitude of other administrative, technical, and stakeholders and interest groups educational bodies adopt them. met in one place to discuss how Conference participants also to address the growing number of recommended that the States take fatalities and serious injuries. the lead by passing adequate motor vehicle laws and setting up suitable Prior to the conference, committees agencies for administering the laws, were established to perform policing the highways, registering research into areas such as planning vehicles, and licensing drivers. and zoning, traffic control, motor vehicles, statistics, and other To the Federal Government, the areas related to road safety. conference assigned the role of These committees reported wide encouragement, assembly and differences in traffic regulations distribution of information, from State to State and city to city. and the development of For instance, twenty States did not recommended practices. Adoption attempt to collect crash statistics, and implementation of these only eight States required reporting recommended practices would be crashes that resulted in personal left to the individual States.

1-10 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS Secretary Hoover called a second to coordinate crash research conference for March 1926. During nationwide. The HRB played a major Uniform the interim between the two part in subsequent efforts to reduce Vehicle Code conferences, a special committee the consequences of crashes.8 A code covering drew up a model “Uniform Vehicle registration and Code” covering registration and Federal Government Role titling of vehicles, titling of vehicles, licensing of licensing of in Highway Development drivers, and drivers, and operation of vehicles on operation of The growing use of motor vehicles the highways. The code incorporated vehicles on the best features of the numerous during the 1920s was mirrored the highways. and varied State laws then on by the expansion of the Federal the statute books. The second Government’s role in funding and conference approved this code building roads. In its early form, the 8 and recommended it to the State Office of Public Roads was organized Source: America’s legislatures as the basis for uniform under the U.S. Department of Highways, 1776-1976: motor vehicle legislation. Agriculture, playing a large role in A History of the funding roadways within national Federal-Aid Program. Studies following this 1926 Federal Highway parks and forests. Administration conference concluded that (U.S. Government determining the causes of crashes Following the Federal Aid Road Act Printing Office, Washington D.C., was far more difficult than they had of 1916, this office would become 1976). presumed. The problem warranted the Bureau of Public Roads (BPR), a sustained program of research charged with working cooperatively by a national organization. The with State highway departments on Conference agreed, and the Highway road projects. Work continued on Research Board (HRB) organized the expansion of highways across the Committee on Causes and the country, and between 1921 and Prevention of Highway Accidents 1939, the distance of paved roads

Balanced Design for Safety In the 1920s and 1930s, it was good Increasing concern for road safety led many engineering practice to design new highway engineers to worry about this highways as much as possible in long inconsistency between posted speed limits straight lines or “tangents.” When it and safe design speed on curves. In 1935, became necessary to change direction, highway engineer Joseph Barnett of the BPR the engineer laid out a circular curve, proposed that all new rural roads conform to the radius of which he selected to fit an “assumed design speed,” a comfortable the ground with the least construction top speed for drivers outside of urban areas. cost, but which could not be less than a With its adoption by American Association certain minimum fixed by department of State Highway Officials in 1938, Barnett’s policy. In practice, engineers made the “balanced design” concept became a curves sharper than this minimum when permanent feature of U.S. roadway design. it was cheaper to do so, but with little Today, standards for designing curves, consistency. Engineers expected motorists such as design speed, curve radius and driving these roads to adjust their speeds superelevation (the tilt of the road through to the varying radii, and on the sharper a curve) are provided in A Policy on curves safe design speed might be Geometric Design of Highways and Streets, considerably lower than the posted produced by the American Association for speed limit. State Highway Transportation Officials.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-11 Safety Signs Before World War I, most States were and created a document that was, in using signs to warn road users of danger effect, a manual of the best practices ahead, particularly at railroad crossings; of the time. Recognizing the need for railroad companies themselves were standard practices for signs in rural and required to post warning signs at all public urban areas, the American Association of road crossings. However, there was little State Highway Officials and the National agreement between States about the Conference on Street and Highway specific design of these warning devices, Safety organized a Joint Committee on and the signs were a variety of shapes, Uniform Traffic Control Devices in 1931 sizes, and colors. and introduced a new manual for national In 1929, the American Engineering Council use in 1935. The manual of best practices surveyed sign practices in all U.S. cities changed over time to become the Manual with a population of more than 50,000 on Uniform Traffic Control Devices.

increased from 387,000 miles to nearly 1.4 million miles.9 The BPR 9 recognized that the antiquated Source: Weingroff, highway system was one of the Richard. A Peaceful contributing causes of the high Campaign Of Progress And Reform: crash toll, but did not go so far as The Federal Highway to identify primary crash causes or Administration at 100. Public recommend potential solutions. Roads Magazine. Vol. 57 No. 2. July During this time, an emphasis was 1993. http://www. placed on expanding the Federal fhwa.dot.gov/ publications/ role in the process of highway publicroads/93fall/ design and development. This p93au1.cfm effort culminated in 1944 when Congress approved the development of a National System of Interstate Highways along with that year’s Federal Aid Highway Act. Though expansive in scope, calling for a 40,000 mile network, the legislation President Harry S. Truman, 1945. was not accompanied by any funds (Source: U.S. Library of Congress) 10 to support the development of these highways. Without funding, Source: Richard his unsuccessful efforts as a U.S. F. Weingroff and the legislation did not significantly senator to enact Federal legislation the assistance of expand the highway system. Sonquela Seabron, on motor vehicle registration and President Dwight D. Eisenhower and Road safety continued to present driver licensing, the President the Federal Role a national concern. In May 1946, said Congress was not yet ready to in Highway Safety, accessed May 23, President Harry S. Truman spoke at interfere with what many perceived 2013, http://www. the Highway Safety Conference to as State prerogatives. However, he fhwa.dot.gov/ rally public support to improve State noted that the Federal Government infrastructure/ safetyin.cfm motor vehicle laws, driver licensing, would not stand aside if the rates of and education. After summarizing highway fatalities continued to rise.10

1-12 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS President Dwight D. Eisenhower speaks to the White House Conference on Highway Safety, 1954. (Source: Eisenhower Presidential Library)

Post War Development the nation’s roads and highways and Growth were unprepared for the increase in traffic. Under wartime restrictions, Economic conditions following States were unable to adequately World War II led to even higher maintain their highways. With levels of driving and automobile widespread operation of overloaded ownership. Personal savings of trucks and reduced maintenance, almost $44 billion created a market the State highway systems were in for housing and other types of worse structural shape post-war goods, chief among them new than before the war. automobiles. Automobile production jumped from a nearly 70,000 in 1945 Development of the Interstate to 3.9 million in 1948. Highway System

Because of this increase in Though the National System of vehicle production, motor vehicle Interstate Highways had been registrations spiked and the number established by legislation in of drivers on the nation’s roads and 1944, little progress was made highways reached unprecedented over the next decade. Without levels. Under wartime rationing of funding, established routes were rubber, and specifically tires, States slow to develop. That changed in had implemented speed controls to 1956, when President Dwight D. reduce wear and tear and improve Eisenhower signed the Federal- tire longevity. With the end of Aid Highway Act of 1956. This rationing and emergency speed legislation linked the development controls at the conclusion of the of the interstate highway system to war, highway travel returned to the interest of national defense and pre-war levels and began a steady assigned funding that would rapidly climb of about 6 percent per year, expand the highway network.11 The which would continue for nearly 11 act established a dedicated funding three decades. stream and a plan for highway http://www. fhwa.dot.gov/ While the increasing popularity of development that launched the publications/ low density housing development nation into an unprecedented era of publicroads/ 06jan/01.cfm (i.e., the suburbs) and the expansion in which new interstate availability of motor vehicles created corridors linked cities and towns to perfect conditions for more driving, one another.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-13 12 13 Despite the enthusiasm of political of the White House marked a and business leaders, the growth transformation in the role of the Source: Richard of this system was not without Federal Government in road safety. F. Weingroff and the assistance of its critics. These critics primarily This role had been growing during Sonquela Seabron, denounced the destruction of homes the Eisenhower administration, but President Dwight D. Eisenhower and and separation of communities became a larger area of emphasis as the Federal Role that sometimes resulted from new fatalities on the nation’s highways in Highway Safety, highways bisecting established climbed toward 50,000. Those in accessed May 23, 2013, http://www. neighborhoods. Though this opposition the federal government observed fhwa.dot.gov/ halted projects in some locations, that the steps taken during the infrastructure/ safetyin.cfm it did not stop the expansion of the previous two decades to reverse the interstate highway system. climbing number of fatalities had failed, and they believed that road 14 Highway Safety Act of 1966 safety should no longer be left solely to the responsibility of the States, http://www. In 1964, the U.S. faced a sharp rise the automobile industry, and the fhwa.dot.gov/ in the number of traffic fatalities. infrastructure/ individual drivers.13 50interstate.cfm An increased number of vehicles on the roadways combined with a This legislation established the public culture that did not prioritize U.S. Department of Transportation 15 roadway safety consciousness led (USDOT) and transformed the to 47,700 deaths on the nation’s Bureau of Public Roads into the Title 49 of the United States Code, highways, an increase of 10 percent Federal Highway Administration Chapter 301, Motor over the number of fatalities that (FHWA). New bureaus were added to Vehicle Safety, occurred in 1963. These deaths https://www.gpo. address safety in areas of growing gov/fdsys/pkg/ prompted the nation to take a hard concern, such as the Bureau of USCODE-2009- look at road safety efforts and Motor Carrier Safety and National title49/html/ USCODE-2009- resulted in Congressional hearings in Highway Safety Bureau (these title49-subtitleVI. March 1965 to raise public awareness would later become the Federal htm of the growing national crisis.12 Motor Carrier Safety Administration and the National Highway Traffic To respond to these trends, the Safety Administration, respectively). nation needed a change of direction The USDOT proceeded to develop 16 in the design and operation of its programs and initiatives and roads and vehicles. This change Federal Motor pave the way for activities still in began with reviewing safety Vehicle Safety place today.14 Standard (FMVSS) standards in these areas and No. 218, https://www.federal conducting research to identify Advances in vehicle design register.gov/ effective measures to improve and policy were also an area of documents/2015/05/ safety. The 1960s was a pivotal emphasis during the 1960s. In 21/2015-11756/ federal-motor- decade for road safety due to the 1968, federal legislation required vehicle-safety- passage of laws that provided vehicles to provide seat belts. 15 standards- motorcycle-helmets funding and new policies. On Federal law also required States to September 9, 1966, President begin implementing motorcycle Lyndon B. Johnson signed the helmet laws in order to qualify for National Traffic and Motor Vehicle particular sources of funding.16 Safety Act of 1966 and the Highway These requirements led to more Safety Act of 1966. The signing widespread implementation of ceremony in the Rose Garden safety policies through the late

1-14 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS President Lyndon B. Johnson signs the National Traffic and Motor Vehicle Safety Act of 1966 and the Highway Safety Act of 1966. (Source: LBJ Presidential Library)

1960s and 1970s. Section 402 of helped by decreasing fuel costs. The the Highway Safety Act established law would later be repealed in 1995, a revenue stream for funding to allowing States to set their own directly support State programs maximum speed limits. aimed at improving road safety. Between 1970 and 2007, there Known as the State and Community were two periods of time when 17 Highway Safety Grant Program, the VMT decreased from the previous funds originally supported a variety Governors Highway year. These years include 1974 and Safety Association. of program areas, including many 1979, each of which saw a roughly Section 402 State many behavioral safety programs and Community 18 billion mile decrease in VMT Highway Safety that are still in existence today. 17 from the previous year.18 As driving Grant Program. http://www.ghsa. Energy Crises and Safety decreased, so did traffic fatalities. org/about/federal- From 1973 to 1974, for example, grant-programs/402 Legislation in the 1970s traffic fatalities went down 16 and 1980s percent – the largest single year decline since 1941-1942.19 Driving 18 The 1970s and 1980s were levels began to increase again characterized by energy crises in http://www. once fuel costs normalized, so fhwa.dot.gov/ 1973 and 1979 that had immediate policyinformation/ the reductions were not sustained and lasting impacts on travel trends. travel_monitoring/ beyond the period of economic tvt.cfm Vehicle Miles Traveled (VMT) stagnation. decreased following each of these events, as Americans drove less The Highway Safety Act of 1973 19 due to rising fuel costs. Strategic established a specific methodology legislative action by Congress, such for improving roadway safety from https://crashstats. nhtsa.dot.gov/Api/ as the National Maximum Speed an engineering perspective. It Public/ViewPub Law of 1974 which prohibited speeds required the States to first survey lication/811346 higher than 55 miles per hour also all hazardous locations and examine

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-15 Ford Model T is released as Revenue Act of 1932 20 the first automobile available establishes first national 1932 1908 to most of the middle class gas tax at 1 cent per gallon Source: “HSIP History,” accessed ROAD SAFETY TIMELINE October 22, 2013, http://safety.fhwa. dot.gov/hsip/gen_ info/hsip_history.cfm Office of Road Inquiry is created, Bureau of which would eventually become the Public Roads Uniform Vehicle Code is and “Subchapter J— developed during the second 1893 Federal Highway Administration 1916 is created

Highway Safety: Part 1926 highway safety conference 924—Highway Safety Improvement Program,” First national conference accessed October on highway safety held

1924 in Washington, DC 21, 2013, http://www. gpo.gov/fdsys/pkg/CFR- 2003-title23-vol1/pdf/ the causes of crashes at these sites. The Federal Motor Vehicle Safety CFR-2003-title23-vol1- chapI-subchapJ.pdf. A benefit/cost analysis was then Standard 213 brought attention performed to prioritize needed to child passenger safety. This improvements. This process set standard was the first to outline 21 the stage for the current safety specific requirements for restraint

Source: “What is management processes and would be systems designed for children. the Motor Carrier refined and improved over the years. Safety Assistance Multimodal Shift in the 1990s Program (MCSAP)?” The Highway Safety Act of 1973 also accessed May 23, 2013, https://www. clarified the relationship between The 1990s saw a shift from federalregister.gov/ the Federal Government and the transportation policies that focused documents/2000/03/ on motor vehicle safety and 21/00-6819/motor- States. The Federal Government carrier-safety- was to direct policy and program efficiency to an acknowledgement of assistance-program components, while the States were alternate modes of transportation, responsible for implementing those such as bicycling, walking and use policies and programs.20 of public transit. The Intermodal 22 Surface Transportation Efficiency During the 1970s, Congress also http://www.iihs.org/ Act of 1991 (ISTEA) added a iihs/topics/laws/ established the Motor Carrier Safety multimodal perspective to the safetybeltuse Assistance Program (MCSAP). Federal-aid highway program. This program provides financial assistance to States to reduce the While ISTEA was not specifically 23 number and severity of crashes focused on transportation safety, it Source: and hazardous materials incidents created some programs to promote “Intermodal Surface safer travel. For example, ISTEA Transportation involving commercial motor Efficiency Act of 1991 vehicles (CMV) through inspection enhanced road safety with new Information,” last and enforcement programs programs that encouraged the updated May 16, 2013, accessed July 05, 2013, focused on trucks, carriers, use of safety belts and motorcycle http://www.fhwa. and driver regulations. 21 helmets.23 The legislation also dot.gov/planning/ required the installation of airbags public_involvement/ Vehicle safety continued to be a archive/legislation/ for drivers and front passengers in istea.cfm. priority in the 1970s and 1980s, as all cars and trucks.24 more States began to implement laws requiring the use of seat belts In 1998, the Transportation Equity 24 and motorcycle helmets. New York Act for the 21st Century (TEA-21) See next page. became the first State to adopt a provided more focus for roadway mandatory seat belt law in 1984, and safety planning by establishing other States soon followed suit.22 safety and security as planning

1-16 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS FA A F F 1971 1956

N F F M S S 1944 S I

1968 24 Highway Safety Act and National Traffic and M S A http://www.history. com/this-day-in- 1966 US D T history/federal- legislation-makes- accuracy, completeness, uniformity airbags-mandatory and accessibility) of State data

needed to identify safety priorities 25 for national, State and local road Source: “TEA-21 25 safety programs. – Transportation Equity Act for the 21st Not to be lost among the TEA-21 Century Fact Sheets,” last modified April 5, legislation, another pivotal moment 2011, accessed June in transportation legislation came in 2, 2013, http://www. fhwa.dot.gov/tea21/ 2000 when an important provision factsheets/index.htm Officers use specialized devices to related to alcohol was included in measure drivers’ blood alcohol content. the USDOT appropriation act. The Blood alcohol appropriation carried a requirement content priorities. Prior to TEA-21, a State or that all States must enact laws to The percentage Metropolitan Planning Organization limit the legal blood alcohol content of alcohol in (MPO) may have incorporated 26 (BAC) of drivers to 0.08 percent. a person’s safety in its goals or long-range This limit was in line with similar blood, used to transportation plan, but specific measure driver limits imposed on drivers in other strategies to increase safety were intoxication. seldom included in statewide and countries, though some European metropolitan planning processes countries limit the legal BAC to 0.05 26 or documents. percent. Rodriguez-Iglesias, TEA-21 established the Highway While 19 States and Washington, C.; Wiliszowski, ClH.; Safety Infrastructure program (not Lacey, J.H. Legislative D.C., had already enacted this law, History of .08 Per to be confused with the Highway the Federal mandate provided a Se Laws, National Safety Improvement Program, Highway Traffic Safety further incentive for other States Administration, which would be developed several Report No. DOT HS years later), which funded safety to do so: States that did not pass 809 286, June 2001 improvement projects to eliminate the law by 2004 would forego a safety problems. portion of their transportation funding. Though specific laws vary, 27 The TEA-21 legislation also encouraged States to adopt and each State now recognizes the legal http://www.ghsa.org/ html/stateinfo/laws/ implement effective programs to limit of 0.08 percent blood alcohol impaired_laws.html improve the quality (e.g. timeliness, content.27

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-17 O ISTEA N SAFETEA MA M S LU 1995 1991 2005 1979 I R L 2012

S New York becomes first TEA S S 1984 1974 1998 O 1973 S A 1993 N M S L

Legislation in the 21st Century the requirement for each State to develop and implement a Strategic Twenty-first century legislation Highway Safety Plan (SHSP).29 continued to move Federal The plans sought to establish transportation funding and data-driven approaches that were policy in the direction of focusing coordinated with a broad range of on multimodal, data-driven stakeholders and utilized a diverse approaches to improving the set of disciplines (e.g., engineering, transportation system. One specific enforcement, education and area of focus was a move toward emergency response). These data- safety planning. Transportation driven plans had to include clear safety planning shifts the focus methods for measuring progress of traditional planning efforts to toward safety goals. a more comprehensive process that integrates safety into The Moving Ahead for Progress in transportation decision-making. the 21st Century Act (MAP-21) was Safety planning encompasses signed into law in 2012. The 2012 corridors and entire transportation legislation transformed the policy networks at the local, regional, and programmatic framework 28 and State levels, as well as for investments in the country’s 28 transportation infrastructure, Source: specific sites. “Transportation enhancing the programs and policies Safety Planning In 2005, Congress passed the Safe, established in 1991. (TSP),” accessed Accountable, Flexible, and Efficient August 13, 2013, MAP-21 doubled funding for road http://safety.fhwa. Transportation Equity Act—A dot.gov/hsip/tsp/ Legacy for Users (SAFETEA-LU). safety improvement projects, and “Transportation strengthened the linkage among Safety Planning Fact SAFETEA-LU raised the stature of Sheet,” accessed Federal road safety programs by modal safety programs and created a August 13, 2013, establishing the Highway Safety positive agenda to make significant http://safety.fhwa. progress in reducing highway dot.gov/hsip/tsp/ Improvement Program (HSIP) as fact_sheet.cfm. a core Federal-aid program tied fatalities and serious injuries. It to strategic safety planning and provided increased focus on the performance. HSIP is one of six importance of high quality data, 29 core Federal-aid programs under transportation infrastructure and the safety of local streets. Title 23 United which funds are apportioned States Code § 148 directly to the States. One of the major elements of the HSIP was

1-18 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS Conclusion

Exploring the history of travel trends and safety in the U.S. helps illustrate how past decisions have led to the transportation system seen today. Safety has not always been a deciding factor in how roads are built. However, today, safety is a top priority of the USDOT.30 30 Most State and local transportation agencies share USDOT’s goal; U.S. Department some have even set goals to reduce of Transportation. Strategic Plans. total traffic fatalities to zero. November 2015. These “vision zero” and “toward https://www. transportation.gov/ zero deaths” goals are guiding mission/budget/ transportation projects by requiring dot-budget-and- safety to be incorporated into every performance- documents# step of project planning, design, StrategicPlans construction and operation.

Future safety issues will certainly arise as technological advancements lead to changes in the vehicle fleet. Autonomous and potentially begin to share the roads with older driverless vehicles are being vehicles, bicyclists, and pedestrians. developed and tested across the As can be learned from the history world. Though safety improvements of road safety in the U.S., complex are touted as a benefit of these problems must be met with safety advanced vehicles, safety will advancements, legislative action, continue to be a priority as they and collaboration.

EXERCISES

JJ RESEARCH a federal transportation law JJ USE https://www.govtrack.us to find a addressed in this chapter and write a transportation bill currently proposed summary about the law, emphasizing or under review by Congress. Describe the safety aspects. how the legislation would be expected to affect road safety. JJ FIND a recent news article that involves road safety (more than just a local news JJ RESEARCH the legal driving Blood article on a recent crash) and write a Alcohol Content (BAC) by state in the summary describing the effort under- U.S. and create a table showing the taken by the public agency, how it was comparison. Select one state where received by the public, and whether it the legal BAC is lower than the federal was shown to be effective in increasing requirement, locate a paper or news road safety. article describing how that BAC level was decided, and write a summary.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-19 CHAPTER 3 FOUNDATIONS OF ROAD SAFETY Multidisciplinary Approaches

Road safety is a complex issue, and any efforts to improve safety must The E’s address not only the roadway but A popular multidisciplinary approach to also road user behavior, vehicle road safety is sometimes referred to as design, interaction between the “four E’s”: Engineering, Education, road users, and the effect of the Enforcement, and Emergency response. roadway on all road users. Road These E’s broadly represent the various disciplines that bring together safety partners include anyone stakeholders who care about making who influences road user safety, the road safe for all users. Sometimes including those in infrastructure a fifth “E” for evaluation is added to safety, behavioral roadway safety, this list to represent the important transportation planning, public role of evaluating what works and what health, public safety and many other doesn’t. This emphasizes the fact that good data is crucial to the improvement disciplines. Each of these disciplines of road safety. is able to provide a unique perspective and each has specific This chapter will discuss methods for addressing road safety. road safety efforts from the It is becoming increasingly common disciplines of roadway design and for these various disciplines to work engineering, public education, in collaboration with one another and enforcement campaigns. to address road safety through Working in collaboration with one comprehensive programs. Instead another, as described above, these of focusing on traditional “silos” groups can share the burden of of activity, agencies hope that this road safety responsibilities and interaction and collaboration among create comprehensive programs to various disciplines will lead to address the various factors that may continued safety improvements. contribute to crashes.

1-20 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS Roadway Design Roadway engineers work on the and Engineering design, construction and system preservation of the roadways. In Several types of transportation particular, engineers are charged professionals are responsible for with designing roads that minimize roadway safety engineering. the chance that crashes will occur Broadly speaking, the roadway while balancing the needs for safety engineering community efficiency and mobility. Engineers includes transportation planners also work to design roads and and engineers. intersection in such a way that minimizes crash severity and Transportation planning plays a injury risk when crashes do occur. critical role in determining the shape Engineers affect the safety of the of the transportation system and built environment by incorporating provides an early opportunity for safety in to the planning process at professionals to address safety needs. the beginning of a project; selecting Before a road project is designed or design alternatives that prioritize built, it is influenced by any number safety considerations; using of comprehensive and strategic design elements that maximize transportation plans that are the safety of each part of the road coordinated to ensure that the system or intersection; ensuring quality being developed is one that matches and safe construction, operation, the vision of the local community. and maintenance of the roads; Planners work with stakeholders and addressing safety problems at such as the general public, business existing locations. owners, policy makers, and advocates to establish plans for how Infrastructure improvements such the transportation system can best as paved shoulders, rumble strips, serve every group’s needs. and improved nighttime visibility may prevent drivers from veering In the past, the traditional planning off the roadway, and still other process focused on economic opportunities exist for improving development, environmental quality, the roadside and road user behavior. and mobility as the three primary For example, when a driver veers concerns. Most States consider off the roadway, it is important to infrastructure safety improvements as provide a roadside environment that part of preservation or improvements reduces the potential for crashes and projects or within operational injury. Roadside slopes and objects changes undertaken by traffic such as drainage structures, trees, offices. States are now able to use and utility poles are examples of the Highway Safety Improvement roadside elements that engineers Program (HSIP) to fund safety can target for improvements to projects in at high priority locations. road safety performance. One This program allows development engineering method to increase of targeted solutions and approaches roadside safety is to create a clear that address the contributing zone—an unobstructed, traversable factors to collisions, thereby roadside area that allows a driver to seeking to achieve a higher return stop safely or regain control of the on safety investments. vehicle that has left the roadway.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-21 Public Education and Countermeasures That Work Enforcement Campaigns Countermeasures That Work31 is a 31 comprehensive guidance document Public education and communications Countermeasures providing details of different programs campaigns are commonly used that Work: A and interventions that are effective to improve road user attitudes Highway safety in improving safety. The guide is and awareness. The structure Countermeasures published regularly by NHTSA. Guide for State and delivery methods of these Highway Safety campaigns can take many forms. Offices, 7th edition, 2013 DOT HS 811 727 However, they generally involve Engineering solutions must materials (media advertisements, incorporate the different needs informational brochures, posters, and preferences of a variety of user presentations, etc.) to inform groups. As mentioned previously, people of a desired behavior and this often means that tough the benefits of such behavior (or decisions and trade-offs must be conversely, the risks of an unwanted made to arrive at infrastructure behavior). solutions that balance the needs of While standalone informational or different users. This trade-off can educational campaigns can improve be illustrated with an example of a awareness or perceptions about road signalized intersection. Improving safety issues, they are unlikely to intersection safety for pedestrians change road user behavior. Rather, may involve adding pedestrian campaigns that educate the public crossing time to the signal or about increased law enforcement separating turn movements to efforts aimed at a particular eliminate high risk conflicts. behavior have been shown to be Protected left-turn phases can effective. Generally referred to as also improve safety for vehicles, as “high-visibility enforcement” these shown previously. But these new campaigns increase the perceived or longer signal phases either add enforcement of a particular law. time to the cycle length or keep When people believe there is a high the same length while reducing probability of being caught, they are time for the through movements. more likely to follow the law. The Regardless, the result is more delay Click it or Ticket campaign is one of to both pedestrians and motorists. the most widely known examples In such situations, it is necessary of high-visibility enforcement. to consider all of these needs and In this case, simply enforcing the select the appropriate signal timing seatbelt law was not sufficient. that meets the needs of all users. The key to this program’s success Adhering to design standards – was the media coverage and other creating nominally safe conditions informational campaigns telling the – is only one aspect of the complex public that law enforcement officers roadway design and engineering are looking for people who are not field. Addressing substantive safety wearing a seatbelt. In other words, through design strategies requires for those people who do not typically an understanding of multiple wear a seatbelt, the law itself perspectives, trade-offs and was not sufficient motivation to user needs. change. The motivation came from a

1-22 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS perceived threat of being caught and ticketed. Targeted Enforcement

When safety professionals analyze To reinforce pedestrian safety laws, police departments can initiate targeted possible educational campaigns, they enforcement operations at crosswalks. must consider the factors that affect Under this approach, a law enforcement people’s behavior and the probability officer in plain clothes will attempt that the campaign will change such to cross the street at an uncontrolled behavior. Simply communicating crosswalk. Drivers who do not yield safety messages and enforcing to the officer will be pulled over and laws may not lead to a change in either cited or warned by patrol vehicles behavior if a road is designed in a waiting beyond the crosswalk. More way that allows (or unintentionally info: http://www.nhtsa.gov/staticfiles/ encourages) unsafe behaviors. For nti/pdf/812059-PedestrianSafetyEnforce example, to address a speeding OperaHowToGuide.pdf problem on a wide multilane arterial where the posted speed is 35 miles per hour, enforcement the road. Supplemental education and education may not be the only and enforcement campaigns can solution. Narrowing the roadway then help reinforce the proper and creating more “visual friction” behavior. This emphasizes the need along the roadside may be needed for cooperation and coordination to alter the desired design speed of between disciplines to accomplish

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-23 meaningful improvements to road safety.

While there is evidence to suggest 32 some success for well-designed and executed safety education campaigns Zegeer, C. V., 32 Blomberg, R. D., when they are targeted at children, Henderson, D., the same results have not been Masten, S. V., Marchetti, L., shown for teens and adults when Levy, M. M., Fan, an educational campaign stands Y., Sandt, L. S., Brown, A., Stutts, alone. Though well-intentioned, J., & Thomas, L. J. these approaches generally assume (2008b). Evaluation that people are not performing of Miami–Dade pedestrian safety the desired behavior simply demonstration because they lack the appropriate project. Transportation information. However, this idea fails Research Record to take into account the fact that, 2073, 1-10. in general, most human behavior is not the result of conscious, rational deliberation. People are largely Bicycle Safer Journey influenced by emotions, values, Bicycle Safer Journey is an educational social context, and culture, among program intended to provide bicycle many other factors. Thus, simply safety skills and education to children. being presented with information The program uses interactive video or facts alone is unlikely to lead to lessons to teach children safe bicycling skills and provides resources for any lasting behavior change. In the parents and teachers. The program context of transportation safety, can be accessed online at http://www. most people do not engage in risky pedbikeinfo.org/bicyclesaferjourney. or undesirable behaviors due to a lack of knowledge about the desired behavior. Instead, people act based influence the pedestrian’s decision on a variety of contributing factors. to cross mid-block (time, ability, weather, etc.), but likely the most For example, consider the behavior important factor is that doing so of a pedestrian on a multi-lane just makes sense. People are wired undivided arterial. The goal of to choose the option that makes the pedestrian is to get to a bus the most intuitive sense. Efforts to stop located directly across the change this behavior only through street from his current location. signs, posters or other educational The pedestrian almost certainly campaigns will likely have only knows that the desired behavior minimal effect. is to walk a quarter mile to the signalized intersection, wait and Similar examples can be found cross with the crossing signal, and throughout the transportation safety then to backtrack a quarter mile to field. Most people already know they the bus station. However, instead should wear their seatbelt, obey the pedestrian chooses to cross in posted speed limit signs, and limit the middle of the block. The fact distractions while driving. Yet some is that there are many factors that people refuse to wear a seatbelt,

1-24 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS Click It or Ticket Click It or Ticket is a successful seat belt and enforcement along with high visibility enforcement campaign that has helped to media coverage to publicize and sustain increase the national seat belt usage rate. the campaign. NHTSA manages this The program uses public education to campaign annually with assistance from communicate the law and risks of not the State Highway Safety offices, law using seat belts in a variety of settings. enforcement agencies, and national- and The campaigns provide waves of education local-paid advertising.

some people speed, and some people text while driving. Knowledge alone Media Campaign Effectiveness is not enough. Well planned and executed media 33 campaigns centered on reducing Successful education and Elder, R.W., et alcohol-impaired driving can be al. Effectiveness enforcement campaigns recognize effective in reducing the occurrence of of mass media the reality of people’s behaviors and alcohol related crashes. A study in 2004 campaigns for apply this knowledge to the safety pointed to a 13 percent decrease in reducing drinking alcohol related crashes following these and driving and efforts. For example, social norms alcohol-involved types of campaigns.33 and cultural influences can provide crashes: a systematic review. some explanation for why certain July 2004. http:// behaviors are common - even those to the areas of distracted driving www.sciencedirect. com/science/ behaviors known to be unsafe. and driving under the influence of article/pii/ Marketing interventions based on alcohol. Such methods provide a S0749379704000467 social norms have been applied way to examine safety problems and

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-25 what might be done to address them reduction in fatalities and serious Strategic through education and enforcement. injuries. Highway Safety Plan Comprehensive A State’s Strategic Highway Safety Plan (SHSP) is an example of a Provides a Safety Programs comprehensive safety plan, and one framework for developing a While each discipline has its own of the best examples of a multi- coordinated and strengths, significant improvements disciplinary, data driven planning comprehensive in roadway safety are more likely effort. A State SHSP provides approach to when a program encompasses a framework for developing a addressing road coordinated and comprehensive safety across many disciplines rather than approach to addressing road safety a State. just one. Interdisciplinary team across a State. In the development of efforts can take on safety problems a State’s SHSP, safety stakeholders using multiple approaches and from across the State and across are therefore greater in scope disciplines will consider all the than individual disciplines data available (i.e., crash, injury working in isolation. The need surveillance, roadway and traffic, for this “multiple approach” vehicle, enforcement, and driver solution requires collaboration data) that will help an agency among many parties. This type of understand where more safety 34 collaboration is most clearly seen emphasis is needed.34 Beyond crash when agencies seek to create a https://safety. records, an agency may choose to fhwa.dot.gov/shsp/ comprehensive safety plan. Creating rely on alternate data sources like guidebook/ a comprehensive safety plan for roadway characteristics and its own a city, county, or state must be a knowledge of crash risk to pursue data driven process. In doing so, systemic safety strategies. A systemic 35 agencies first begin by analyzing approach proactively identifies their safety data to identify locations that may have a high risk http://safety.fhwa. dot.gov/systemic emphasis areas where concentrated of crashes but where the risk has efforts are likely to yield the largest not yet resulted in actual crashes.35

1-26 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS Demographic data showing where for effective collaboration and population growth has occurred, establishing a process to support or where it is expected, can also collaborative efforts are two ways influence an agency’s safety plans. to overcome these barriers. One One of the most critical components way to create a foundation for of the SHSP is an evaluation of past collaboration is to ensure that each efforts, so that the agency can know agency understands the impact what strategies are working and so that its actions have on road safety that progress toward goals can be and that each makes safety its top measured and tracked over time. priority. The example of a State Strategic Highway Safety Plan shows Road safety planning, like the field of this type of collaboration. The SHSP safety itself, is multidisciplinary in process brings together all potential nature and relies upon the expertise areas of safety emphasis, including and involvement of numerous intersections, non-motorized perspectives. Once developed, these users, rural crashes, and others, safety plans influence activities and uses a data driven approach ranging from roadway design and to identify priorities and areas engineering to law enforcement and of need. This foundation can be safety education. further strengthened by identifying which agencies or organizations are Each of the agencies and responsible for implementing each of organizations involved in the strategies identified in the SHSP. transportation safety brings a unique and valuable perspective to bear on In the U.S., no single player manages the roadway safety problem. Their all programs and disciplines that competing philosophies, worldviews impact road safety. Therefore, and problem solving approaches, collaboration among all players is however, can make collaboration fundamental to consistently reduce difficult. Creating a foundation serious injuries and fatalities.

EXERCISES

JJ FIND the website for your State or consider the many different types of local road safety program. Identify programs and strategies that can be initiatives that your State or local used to improve road safety. agency is implementing in the areas of JJ SELECT an area of concern, either a planning, engineering, education, and specific type of road user or an unsafe enforcement. behavior, and discuss how road safety JJ CONSIDER a hypothetical situation in this topic area could be addressed or where it is your job to convene a team improved through multiple disciplines. of professionals to visit a high crash Possible topics include: intersection and explore possible JJ Older drivers solutions to the safety problem. Create a list of the people who should be JJ Underage drinking included on that team and briefly JJ Fatigued or drowsy driving describe each person’s role. Be sure to JJ Pedestrians

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-27 CHAPTER 4 FOUNDATIONS OF ROAD SAFETY Road Users

Drivers of motor vehicles are far However, despite the priority given from the only users of the road, to drivers of passenger vehicle, despite accounting for the majority there remain many unresolved of trips taken in the U.S. The public safety issues for these drivers. At right-of-way on most roads is the core of most of these issues are usually shared by a number of the driver’s actions while navigating different users, traveling by a the road network. Engineers may variety of modes for any number of work to make a road nominally different reasons. Transportation safe by ensuring it follows the professionals must understand latest recommendations and design the mobility and safety needs of standards. However, drivers do not different user groups and how always interact with the road system they interact with one another to as road designers expect them to. gain a better understanding of Thus, a nominally safe road may safety problems and their be much less safe in a substantive potential solutions. sense. While the common reaction has been to assume that some Road user groups include: fault or “driver error” led to the JJ Passenger vehicle drivers crash, this approach fails to take and occupants into account a common behavioral JJ Drivers of trucks principle known as behavioral and other large vehicles adaptation. Simply put, behavioral adaptation refers to the unconscious JJ Motorcyclists process by which people react to JJ Pedestrians their environment -- people cannot JJ Bicyclists be considered to be a constant in the system. Passenger Vehicle Drivers and Occupants Consider a town that wants to resurface and widen a two-lane Passenger vehicles are typically collector roadway through an defined as sedans, pickup trucks, older neighborhood with mature minivans, and sport utility vehicles street trees. The existing road has and represent the primary mode 9.5 foot wide lanes, a 30 mi/h (48 of transportation for the majority ki/h) speed limit, and street trees of Americans. Since these vehicles between the roadway and sidewalk. account for the vast majority of Design guidance may suggest a registered vehicles and vehicle typical lane width of 12 feet and a miles traveled, it is not surprising wider roadside clear zone. It is easy that much of the transportation to assume that the safest choice infrastructure prioritizes the needs would be to design a road with the of these drivers. widest lanes possible and removal

1-28 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS The intended speed of this road is 35 miles per hour, but the wide design of the road and the number of lanes leads drivers to drive much faster. of the roadside hazards. However, hazards, people will not maintain after this resurfacing and widening their original behavior. In fact, project was completed, both traffic the assumption should be that speeds and crash severity along this people will adapt to this change roadway may increase considerably. and unconsciously change their On the surface, this may seem behavior accordingly, in this case by counterintuitive. increasing their speed.

In essence, most people drive at Behavioral adaptation is not a speed that feels safe to them. specific to passenger vehicles. To reach this “safe speed,” When designing the transportation people unconsciously assess the infrastructure, engineers must roadway and its characteristics. consider how human behavior plays Navigating a narrow, curvy road affects all roadway users. Roadway with significant roadside hazards is more challenging than navigating a designers must design roads not straight, wide road with large clear for the way in which they would zones, so people unconsciously like users to behave, but for the drive slower and more cautiously on way in which users actually behave. the narrow road. When the driving Behavior of drivers and other road task is made easier by widening users will be covered in a greater the lanes and removing roadside detail in Unit 2.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-29 Drivers of Trucks and Road designs that accommodate Other Large Vehicles large vehicles can sometimes be directly at odds with designs that Much of the transportation favor pedestrians and bicyclists. network across the country serves For example, a pedestrian is an important commercial need. more comfortable crossing an Truck drivers, in particular, play intersection if the turns are very a significant role in the national tight, where the distance between economy and are responsible for corners in minimized to shorten moving goods between and within the walking distance and decrease cities and States. Large trucks the time in the roadway. Large account for only 4 percent of trucks and buses, however, require registered vehicles in the U.S., but a larger turning radius (when they make up 9 percent of total vehicle miles traveled and accounted compared to passenger vehicles) for 12 percent of total traffic fatalities in order to turn safely. When in 2013.36 These large trucks share designing intersections for large 36 37 space on the roads with passenger trucks, designers are tempted to http://www-nrd. vehicles, and have their own safety increase the amount of space in an nhtsa.dot.gov/ needs. Nationally in 2013, there were intersection and widen the corners. Pubs/812150.pdf just under 4,000 people killed in This change will make the turn crashes involving large trucks, and easier, but it will also be more 71 percent of them were occupants uncomfortable (and possibly less of the other vehicle involved in the safe) for pedestrians. As described 38 crash. However, large truck safety previously, these trade-offs need has improved over time. Between to be assessed and discussed when http://www. 2004 and 2013, the miles covered by fhwa.dot.gov/ planning road projects. policyinformation/ large trucks increased by roughly 25 statistics/2013/pdf/ percent, while fatalities involving Motorcyclists mv1.pdf large trucks decreased by about 20 percent (from 4,902 to 3,906).37 In recent years, motorcycling has become increasingly popular 39 Commercial trucks are not the throughout the U.S. Since 2000 the only large vehicles on the roads. https://www.fhwa. number of registered motorcycles Transit vehicles occupy space on dot.gov/ohim/hs00/ in the U.S. has nearly doubled. 38 39 pdf/mv1.pdf our roadways as well, though they The result was a 71% increase in typically serve pedestrians and the number of motorcyclist bicyclists. Transit vehicles that share fatalities (from 2,897 in 2000 40 space with passenger vehicles also to 4,957 in 2012). Motorcyclists have unique needs and challenges. http://www-fars. represented 15 percent of all traffic nhtsa.dot.gov/ Many of the safety issues associated Main/index.aspx with transit vehicles are similar to fatalities in 2012, compared to those of large trucks. Bus operators just 7 percent of fatalities in 2000. 40 have to consider how stopping Motorcyclists are significantly 41 in traffic impacts the flow and overrepresented in traffic fatalities operation of the transportation since they account for only http://www-nrd. nhtsa.dot.gov/ system, and must also consider the 3 percent of registered vehicles Pubs/812035.pdf safety of their passengers boarding and 0.7 percent of total vehicle and disembarking the vehicle. miles traveled in 2012.41

1-30 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS parked vehicle to the front door of a business. Some walking trips are taken out of necessity – not all households own a vehicle, 42 42 and children and individuals with disabilities may not have the option https://info.ornl.gov/ to drive. Many more walking trips sites/publications/ Files/Pub50854.pdf are taken by choice, especially for exercise or health. A 2012 survey found that 39 percent of trips taken by foot are done for exercise or 43 personal health purposes. Walking 43 is also more common in densely populated urban areas, due to the http://www. pedbikeinfo.org/ close proximity of destinations and data/factsheet_ other services like transit stations. general.cfm

Regardless of the reasons for walking, this mode accounts for nearly 11 percent of all trips taken in the U.S., according to the 2009 National Household Travel Survey (NHTS). 44 The NHTS shows that 44 about a third of all trips taken in the U.S. are shorter than one mile, http://www. pedbikeinfo.org/ In general, many of the roadway and 35 percent of these trips are cms/downloads/15- modifications done to improve taken by foot. In the 2005 Traveler year_report.pdf safety for passenger vehicles can Opinion and Perception Survey pose a challenge for motorcyclists. (TOP), conducted by FHWA, data Rumble strips can be difficult to showed that about 107.4 million traverse, especially at low speeds. Americans (51 percent of the Guard rails, in particular cable traveling public) use walking as a regular mode of travel. 45 barriers, can present a serious 45 hazard to a motorcyclist impacting Pedestrians (along with bicyclists) one at a high speed. Within the http://www.fhwa. are among the most vulnerable road dot.gov/reports/ driving environment, motorcyclists users, and this is reflected in crash traveleropinions/ are small compared to larger 1.htm data. The 4,743 pedestrians killed vehicles and can be difficult to see, in 2012 represented 14.1 percent especially early or late in the day of total traffic fatalities in the U.S. when lighting levels are lower. that year. Between 2008 and 2012, Pedestrians motor vehicle fatalities decreased 13 percent, while pedestrian fatalities Walking is the most basic form increased 8 percent. Within the of transportation. At some point population of pedestrians, there during a typical day, nearly every are certain groups which are person is a pedestrian. People walk especially vulnerable. These include to get to a bus station, to go from young children, older adults, and home to school, or to get from a individuals with disabilities.

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-31 Before (left) and after (right) pictures of Stone Way North. (Source: Seattle DOT)

Road Diet In 2008, Seattle Department of “sharrows”). The cross section reduced Transportation implemented a road diet the number of travel lanes to add bicycle on a 1.2-mile (1.9-kilometer) section of lanes and parking on both sides. The Stone Way North from N 34th Street to N resulting corridor saw a decrease in the 50th Street. In addition to serving motor 85th percentile speed, while the overall vehicles, this segment of Stone Way North capacity remained relatively unchanged helps connect a bicycle path with a park. despite the reduction in the number Within five blocks are eight schools, two of lanes. The number of bicyclists on libraries, and five parks. the corridor increased by 35 percent, but crashes involving bicyclists did not The modified segment was originally increase. Pedestrian crashes declined by a four-lane roadway carrying 13,000 80 percent following the project. vehicles per day. For this corridor, the city’s 2007 bicycle master plan Summarized from a 2011 Public Roads recommended climbing lanes and shared article: http://www.fhwa.dot.gov/publications/ lane markings (previously known as publicroads/11septoct/05.cfm

Young children are a vulnerable impaired. These pedestrians have road user group, and may be more increased challenges in navigating likely than adults to rely on walking the road safely, particularly at as a primary transportation mode street crossings. Challenges faced – especially before they are old by a blind or visually impaired enough to drive. One area of concern pedestrian include finding the is creating a safe environment for appropriate crossing point at an young children when they walk to intersection corner or midblock school. Safety professionals need location, determining the appropriate to ensure that sidewalks and street time to cross, and crossing quickly crossings have the appropriate and accurately. Both crossing and measures to assist children in traversing a sloped sidewalk can be traveling safely, and educate equally difficult for an individual in a children about safe walking. wheelchair, where even slight cracks Another vulnerable portion of the or bumps in the sidewalk can present pedestrian population includes major obstacles. The difficulties of those who are blind or visually these challenges increase at locations

1-32 UNIT 1: FOUNDATIONS OF ROAD SAFETY ROAD SAFETY FUNDAMENTALS with unusual geometry, irregularly Drivers and pedestrians share 46 timed signals, or non-stop vehicle responsibility for many pedestrian flow such as roundabouts and fatalities, as both parties attempt Source: “Identifying Countermeasure channelized turn lanes. to navigate through the same Strategies to space at the same time. Though Increase Safety to Older adults face many challenges Older Pedestrians,” we know that certain factors are National Highway as well. There are a number of Traffic Safety likely to result in more severe age-related changes that affect the Administration, 1. functional ability of older adults pedestrian crashes, such as speed 47 to safely walk and cross the street. , no single cause stands out as These changes include diminished the major contributor to pedestrian 47 crashes. For this reason, no single physical capability, sensory https://www. perception, cognitive skills and lag countermeasure alone would likely aaafoundation.org/ make a substantial impact on the sites/default/files/ in reflexive responses. Eyesight 2011Pedestrian deterioration can diminish an older number of pedestrian crashes. A RiskVsSpeed.pdf person’s ability to see and read successful countermeasure program guide signs, slow their reaction time should use a mix of engineering, and decrease their ability to gauge environmental, educational and 48 a vehicle’s approaching speed or enforcement measures to improve 46 48 Source: “Identifying proximity. pedestrian safety. Countermeasure Strategies to Increase Safety to Older Pedestrians,” National Highway Traffic Safety Administration, 36

ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-33 Bicyclists bicycles. Intersections can also pose a challenge to bicycle riders Bicyclists were some of the first when they include high volumes users of U.S. roads, and the group of turning traffic and a large that made the earliest push to number of lanes. These barriers improve road conditions. In recent to bicycling, busy street segments years, bicycling has seen a rise in and intersections, often discourage popularity for both recreation potential riders even when the rest and transportation. Data from of a bicycle network is comfortable. the 2009 NHTS showed that while Many bicyclists are willing to go out only 1 percent of all trips are of their way to use a route that has taken by bicycle, the number of lower vehicle volumes and speeds, or bicycle trips doubled between 49 bicycle facilities that are separated 1990 and 2009.49 from traffic. Safe bicycle facilities http://www. pedbikeinfo.org/ While bicyclists account for only 1 can also improve connections to cms/downloads/ percent of all trips, the 726 bicyclist shopping, transit, jobs, schools, and 15-year_report.pdf fatalities in 2012 represented 2 essential services. percent of all traffic fatalities that year.50 While the number of Conclusion 50 bicyclists killed has risen only Successful road safety programs http://www-nrd. slightly since 2008, the decline in will consider the needs of all users nhtsa.dot.gov/ motor vehicle deaths means that Pubs/812018.pdf when planning and developing bicyclists account for an increasing transportation projects. Each user share of total traffic fatalities. group plays an important role in Bicyclists face unique challenges the transportation system, and as road users. More often than not, each has unique safety needs that bicyclists share space with motor safety professionals must consider. vehicles and are considered legal Road user decisions are influenced users of the road in most locations. by a variety of factors, and the Many potential bicycle riders are combinations of factors that result not comfortable sharing the road in particular travel behavior cannot with heavy vehicular traffic and easily be categorized or understood may be deterred from riding their in simple terms.

EXERCISES

JJ PROVIDE an example of a road index.aspx). Use the data available project where the changes resulted in for the most recent year to document improvements for one user group, but fatality numbers for the different road negatively impacted another group. This user groups discussed in this chapter example could be hypothetical or based (e.g. motorists, pedestrians, bicyclists). on a real world experience. What other information on road user JJ VISIT the Fatality Analysis Reporting safety can you find with the tools System (FARS) Encyclopedia home page available in FARS, and what data is (http://www-fars.nhtsa.dot.gov/Main/ not included?

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ROAD SAFETY FUNDAMENTALS UNIT 1: FOUNDATIONS OF ROAD SAFETY 1-35 UNIT 2 Human Behavior and Road Safety

LEARNING OBJECTIVES

After reading the chapters and completing JJ EXPLAIN why it is important to exercises in Unit 1, the reader will be able to: consider the nature of human behavior when designing and JJ EXPLAIN the systems that drive human implementing systems or programs behavior and give examples of each CHAPTER 5 HUMAN BEHAVIOR AND ROAD SAFETY Understanding Human Behavior

Introduction disease has been nearly eradicated — the only human disease to be Guinea worm disease is a parasitic eradicated besides smallpox2,3. How infection that occurs in remote were such large advances made in parts of Africa. Symptoms of Guinea only 30 years, and what does this worm disease can be debilitating have to do with road safety? and lead to secondary infections, both of which can affect an infected Unlike smallpox, there are no known person’s ability to perform everyday medicines or vaccines that prevent tasks including working, harvesting Guinea worm disease. Eradication, therefore, required a different food and caring for children. The 1 disease is caused by drinking water approach: changing human contaminated with Guinea worm behavior. Cairncross, S., Muller, R., and larvae. When a worm is mature, The Human Factor Zagaria, N. (2002). it creates a painful blister on the Dracunculiasis (Guinea Worm infected person’s skin. If the person A report from the National Disease) and immerses the affected body part Cooperative Highway Research the Eradication Initiative. Clinical in water, it can temporarily relieve Program (NCHRP) defines “human Microbiology the pain from the blister. However, factors” as follows: Reviews, 223-246. this also allows the worm to release Human factors is an applied, scientific eggs into the water, continuing the discipline that tries to enhance the infection cycle by spreading the 2 relationship between devices and disease to others1. systems, and the people who are meant World Health Organization and There were 3.5 million cases of to use them. As a discipline, human the Carter Center, Guinea worm disease throughout factors approaches system design with Eradication of the world in 1986. By 2015, there Guinea Worm the “user” as its focal point. Human Disease: Case were only 22 cases. In 30 years the factors practitioners bring expert Statement, 2016. Available at: https:// www.cartercenter. org/resources/pdfs/ health/guinea_ worm/2016-gw-case- statement.pdf

3

WHO, Dracunculiasis Fact Sheet. May 2016. Available at: http://www.who. int/mediacentre/ factsheets/fs359/en/

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-1 knowledge concerning the capabilities two different systems – a deliberate, 4 and limitations of human beings that rational system (deliberative) and John L. Campbell, are important for the design of devices an implicit, unconscious system Monica G. Lichty; et 4 5 al. (2012). National and systems of many kinds. (intuitive) . Cooperative Highway Research In road safety, the term human The deliberative system is a Program Report factors is typically used to describe 600: Human conscious system wherein a person Factors Guidelines how people respond to the considers information using rational for Road Systems roadway environment. However, (Second Edition). thought, logic and reasoning in Washington, D.C.: people are not simply users of the deciding on an action. Transportation transportation system. Humans Research Board. also design, engineer, build and For example: maintain the roadway environment, When driving home after work, the vehicles using it and the laws 5 a driver decides to change routes governing behavior of roadway users to avoid an area that is usually Kahneman, D. (2011) and vehicle manufacturers. In that congested at this time of day. Thinking, Fast and sense, the entire transportation Slow. Farrar, Straus and Giroux system is a product of human In this example, the driver factors. The term human factors considered the available information conveys an oversimplified notion (time of day and previous of the role of human behavior in experience with that location) transportation safety. The human and made a conscious decision to part of the equation is more complex take another route. than simply a list of discrete factors. The intuitive system is an implicit, Key Principles of unconscious process by which Human Behavior a person makes nearly instantaneous decisions and To understand human behavior, it is takes a resulting action. important to bear in mind four key principles. For example:

JJ Human behavior is guided by two As a driver approaches a signalized different systems (deliberative intersection, the light turns yellow. and intuitive). Without conscious thought, the driver either proceeds through the JJ Humans are not exclusively intersection or comes to a stop. logical, rational beings. In this example, the driver receives JJ Human behavior is heavily information from the environment influenced by the environment. (the yellow light), combines it with JJ Humans make mistakes. an understanding of the specific circumstance based on the driver’s Let’s discuss these concepts as they previous experiences, and takes an relate to road safety. action almost immediately. It is Human behavior is guided important to realize the intuitive by two different systems system acts nearly instantaneously without the driver’s awareness of Human behavior is largely guided by the process.

2-2 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS We often incorrectly assume that Humans are not exclusively human behavior is largely controlled logical, rational beings by the deliberative system when, in fact, most behaviors are a result Although people take in and of the intuitive system. In other interpret information, they do so in words, most human behavior is not the context of a number of factors, the result of conscious, rational such as prior experience, emotions, deliberation. For most actions, we cultural norms, moral beliefs, social don’t have enough time or available pressures, convenience, habits and information to do a logical analysis financial considerations, among before acting. The intuitive system many others. Rational calculations allows us to act without this time- based on objective evidence are consuming conscious decision- often not even possible, and when making process. they are, they must compete with these other influences. This is why To think of this another way, people often make decisions that are consider the deliberative system not necessarily the most appropriate as similar to the decision making choice for their health and well- process of a computer. Computers being. function exclusively using a deliberative system. They take We know that cooking dinner in information, process it using at home may be healthier, but explicit algorithms and deliver a sometimes it is easier and more result. However, humans do not convenient to have a pizza delivered function this way. They generally instead. We know we should exercise make decisions that appear to reflect more and get the recommended instinctual processes rather than amount of sleep each night, but systematic rational considerations. work, family and other obligations

Flossing and human behavior At some point in your life, you have they lack knowledge about the potential probably been told that regular flossing consequences, benefits or alternatives. is good for your dental health. Through Surely, if people simply were aware of the the years, you’ve likely had conversations benefits of flossing or the consequences about flossing with your dentist or dental of not flossing, they would change their hygienist who encouraged you to floss behavior and become regular flossers. This more. Perhaps they showed you the proper approach appeals to the belief that human way to floss and sent you home with your behavior is rational. own floss in an effort to encourage you Although commonly used, this approach to start. For a few days or weeks after the fails to take into account the complexities appointment, you may have deliberately of human behavior. Other factors influence flossed more regularly. But if you’re like our behaviors – flossing is inconvenient, most people, you soon reverted to old takes time and can be uncomfortable. The habits, and the floss sat unused in a negative consequences of not flossing (e.g., cabinet. Why do we do this? gum disease) are not immediately visible. Typically, programs aimed at influencing Although people repeatedly hear messages human behavior take an educational or explaining why flossing is important, rates informational approach on the assumption of flossing among the general population that people act a certain way because remain low.

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-3 can make this difficult. We know we should get a flu shot, but a fear of needles may keep us away.

Humans are largely intuitive beings which means their actions are rarely the result of a systematic, rational decision making process. For years, many people did not brush their teeth daily, even though the benefits of brushing were widely known. 6 It was not until mint flavoring

Duhigg, Charles. was added to toothpaste that daily The Power of Habit: brushing became the norm. That Optical Speed Bars Why We Do What is, information about the benefits We Do in Life and Optical Speed Bars (OSBs) have Business of brushing did little to change shown promise in reducing vehicle behavior; what convinced people speeds in advance of hazardous 7 to brush was a desire for the clean locations . OSBs are a series of white rectangular markings, placed just 7 feeling they associated with the inside both edges of the travel lane mint.6 Because the factors that and spaced progressively closer, to Gates TJ, Qin X, Noyce DA. affect human behavior are complex create the illusion of increasing speed Effectiveness of and interrelated, behavior is not when traveling at a constant rate as Experimental easily changed. When attempting well as the impression of a narrower Transverse-Bar lane8. A compelling characteristic of Pavement Marking to change the behavior of others, optical speed bars is that they operate as Speed-Reduction we tend to assume that people are Treatment on on intuitive, rather than conscious, Freeway Curves. entirely logical and rational beings. decisions made by drivers/riders. By In Transportation However, experience repeatedly creating a sense of increasing speed Research Record: shows this is not the case. as riders approach a dangerous curve, Journal of the they should induce riders to slow down Transportation Research Board, No. This situation is not unique to – as an instinctive reaction rather than 2056, Transportation dental hygiene. We regularly do a conscious decision. Research Board of the National things that we generally realize are Academies, not in our best interest. We don’t eat Washington, D.C., social and organizational contexts, the recommended amounts of fruits 2008, pp. 95–103. such as policies and social norms. and vegetables. We don’t get enough sleep. We don’t exercise as much as Given that most behavior is 8 we should. Think about examples intuitive, people generally do from your own life. not know the true reasons for Federal Highway Administration. Human behavior is heavily their actions, nor can they validly Engineering articulate what might influence their Countermeasures for Reducing influenced by the environment actions. People can usually provide Speeds: A explanations for their behavior after Desktop Reference Often the environment has a much of Potential stronger influence on a person’s the fact, but research shows people Effectiveness. are often not aware of the strong http://safety.fhwa. behavior than internal conditions dot.gov/roadway_ (e.g., attitudes and personality) influence of environmental factors dept/horicurves/ commonly assumed to be influential. on their behavior. An example in fhwasa07002/ch7. cfm. The environment includes the Unit 1 of this book describes a town physical environment, as well as that aims to resurface and widen a

2-4 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS Environment affects behavior Research has shown that people are more no behavior modeling (eight donations likely to help another person (in a non- in the modeled condition versus one emergency situation) if they see someone donation in the control condition). Further, else helping first. Social psychologist when people in the modeled condition Robert Cialdini demonstrated this by were asked why they donated, no one counting donations given to a street realized that they had been influenced musician with and without a colleague first by the behavior of another person. modeling the behavior by donating money. Instead, they attributed their donations He found that many more people gave the to something else, such as enjoyment of musician money when the behavior was the song or how they felt about the person modeled than in the control condition with playing the music9,10,11. 9 Cialdini. R.B. (20005). Basic two-lane collector roadway through what they should do in a given Social Influence Is 12 Underestimated. a neighborhood with mature trees. situation . Psychological However, after completing the Inquiry, 16: 158-161 project, both speeds and crash Humans make mistakes severity increased. Behavioral Both our deliberative and intuitive adaptation refers to the unconscious 10 systems can lead us to make process by which people react to mistakes. Actions reached by a Cialdini, R.B., their environment. While driving, deliberative process can be mistaken Demaine, L.J., people unconsciously assess the Sagarin, B.J., Barrett, if we fail to consider all relevant roadway and its characteristics and D.W., Rhoads, information or if we process it K., & Winter, P.L. modify their behaviors accordingly. (2006). Managing incorrectly. Similarly, our intuitive social norms for This may seem counterintuitive, system can lead to errors in persuasive impact. but as discussed, human behavior is situations with which we have little Social Influence, 1: 3-15 an intuitive process that is heavily or no experience. Experience helps to influenced by the environment. A refine the intuitive processes, so the likelihood of mistakes declines with wider road with limited roadside 11 hazards feels safer and people exposure to situations. However, unconsciously adapt their behavior mistakes are inevitable and the Cialdini, R.B. (2007). Descriptive accordingly. You should assume transportation infrastructure needs social norms as people would not maintain their to be designed with the recognition underappreciated original behavior when the driving that road users will make mistakes sources of social control. environment is changed. and that they will often make them Psychometrika, 72: in predictable ways. 263-268 Roadway designers must design roads not for the way in which they Have you ever looked down at your would like users to behave, but for speedometer and realized that you the way in which users actually were driving substantially over the will behave. In general, people speed limit? You probably didn’t don’t just do what they are told to make a conscious (deliberative) 12 do — by a sign, a law or another decision to exceed the speed limit. Etzioni, Amitai. person. Instead, they integrate Instead, you reached that speed by Human Beings Are information from many parts of taking cues about the proper speed Not Very Easy To their environment along with their from your environment (intuitive). Change After All, Saturday Review, own historical experience as they Characteristics of the road, such as June, 1972. determine (usually non-consciously) wide lanes, multiple travel lanes,

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-5 FIGURE 2-1: Example of unconscious clues leading to higher speed

presence of a median and long with very few other vehicles, the gentle curves, convey the message only clear clue to one’s speed is that the road can accommodate the speedometer. high speeds. Additionally, the speed Roads constructed according to the of other vehicles is a particularly recommended design standards may salient indicator of the right speed. be considered safe, but in reality, Recall this example from Unit 1 they may only be nominally safe. (Figure 1-1). Although the posted The fact that some road designs speed limit is 35 mph, many people encourage higher speeds can drive much faster than that. This is make it substantively unsafe. The not because they all have a blatant transportation system is designed, disregard for safety. Instead, they built, maintained, governed and are unconsciously taking cues used by humans. It is often cited from their environment, which is that human error contributes to telling them it is safe to travel at a more than 90% of traffic crashes, higher speed. Add to this the fact most often referring to a road user that modern vehicles have been error. However, it is important to engineered for occupant comfort, so remember that errors by road users many of the auditory and haptic cues are not the only human errors that (e.g., wind noise, bumps, road noise, can occur. etc.) that previously gave drivers For example: feedback about their speed have been eliminated. On a road On a rural two-lane road, an SUV

2-6 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS driver over-compensates when a tire in airplane crashes, it is quite rare slips off the roadway causing the that any single factor in a motor vehicle to roll over and strike a tree vehicle crash was the sole reason for on the opposite side of the road. the crash or for its severity.

Where was the human error in Meeting nominal safety does not this example? Was it in the driver guarantee that a crash will never who didn’t stay on the road and occur, nor does it guarantee that overcompensated with steering? Was users will behave in the intended the road maintained improperly or way. Those in charge of the road inadequately? Could the crash have should use professional judgement been prevented if edgeline rumble to prioritize safety improvements strips had been installed, or if the and select appropriate designs road had a paved shoulder instead within a range of options based on of a soft gravel shoulder? Should the consideration of road user behavior. tree next to the roadway have been Unit 3 discusses how many kinds removed? Could SUVs be designed so of data, such as crash data and they are less susceptible to roll over? behavioral observation, can be used The answer is that a combination to evaluate the substantive safety of of several of these caused the crash, the road. not simply the driver’s error. Just as

EXERCISES

JJ MAKE a list of your own driving drivers have independently made the behaviors. What behaviors involve the same mistake at the same location. deliberative system? What behaviors What characteristics of the roadway — are intuitive? as designed or built — may have contributed to this cluster of crashes? JJ WORK with your state department of What modifications might be made that transportation to identify a crash cluster would not be offset by in your area. It’s highly unlikely that many behavioral adaptation?

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-7 CHAPTER 6 HUMAN BEHAVIOR AND ROAD SAFETY Changing Human Behavior

Let’s return to the Guinea worm though changing human behavior disease example. You may be is exceedingly difficult, it is wondering why something so possible to achieve behavior change. seemingly unrelated to improving However, this requires that we take safety in a modern transportation into account the nature of human system was used to introduce this behavior instead of assuming that unit. The fact that Guinea worm simply providing information is disease is nearly extinct in only 30 sufficient. years is a tremendous achievement. The fact that it was done through Understanding factors that behavior change alone, without the influence human behavior use of vaccines or medication, is To change human behavior, unprecedented. it is important to identify and Road safety professionals would understand not only the target be wise to consider the successful behavior but also any other factors approach to eradicate Guinea worm that influence the behavior. disease. Although the desired Attempting to change a behavior behaviors may be different, the without a full understanding of general strategies for influencing the many contributing factors will human behavior are the same. Even almost certainly fail.

FIGURE 2-2: Guinea worm disease hotspots in Africa

2-8 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS

Immediate benefit

FIGURE 2-3: Guinea worm disease factors, behaviors and outcomes

Doctors knew that Guinea disease was transmitted. worm disease spreads by people JJ Lack of immediate consequences drinking contaminated water, and – Guinea worm disease contamination of the water supply symptoms did not appear until occurred when an infected person used the water supply to temporarily one year post-infection. relieve the symptoms of infection. Why were people using drinking Hence, the eradication campaign water to relieve the pain caused by focused on two main behaviors: the infection?

JJ Drinking contaminated water JJ Immediate benefit– Water JJ Using drinking water sources submersion resulted in to temporarily relieve the pain immediate pain relief. caused by the infection JJ Limited availability of water – Simply identifying these behaviors Because water is scarce, most was not sufficient. In order to be water sources were used for successful, public health officials drinking. considered many other factors JJ Unavailability of alternative influencing these behaviors. treatments – The lack of medical Why were people drinking infrastructure meant limited contaminated water? access to treatment options.

JJ Availability - Uncontaminated JJ Money – People lacked financial drinking water may not have resources to obtain medical been available in the community. treatment even when available.

JJ Money – People and JJ Understanding – People lacked communities lacked financial knowledge about how the resources to obtain clean disease is transmitted. drinking water. A thorough understanding of the JJ Understanding – People did factors that influence behavior is not know that the water was necessary to develop a plan for contaminated and/or how the behavior change.

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-9 To develop a plan, we cannot merely comprehensive approach. look for the cause of the outcome, instead we need to look for the Approaches to weak links in the causal chain and Changing Behavior intervene at these links. In the case of Guinea worm disease, the limited We are constantly exposed to attempts to influence our behavior. availability of water and lack of Consider the following things that understanding about the disease you may encounter in everyday life: and its transmission were factors influencing both behaviors. Thus, JJ A brochure in your doctor’s these factors were targeted in the office about the benefits of intervention. getting a flu shot

Public health officials informed the JJ A requirement that restaurants people about the dangers of drinking include nutritional information contaminated water and how the in their menu water was becoming contaminated. JJ Stores that charge for plastic However, they knew that simply shopping bags providing this information would not be sufficient. JJ Public service announcements (PSAs) about bullying In order to make the right behavior the easy choice, officials combined JJ Cities that provide large recycling education with environmental bins and small garbage bins change – they educated people on J guinea worm disease and made J A law requiring that everyone wear seatbelts clean water more accessible. Water sources known to be Most of these attempts either contaminated were treated to provide information (e.g., a brochure prevent transmission, and new clean with information about flu shots water sources were created. When or a PSA detailing the negative water sources could not be treated, impact of bullying), or they change villagers were given cloth filters to the environment in such a way decontaminate their water before to encourage a different behavior drinking. When people had access (e.g., stores that charge for plastic to clean water, they were less likely shopping bags or cities that provide to drink contaminated water, thus large recycling bins and small 13 significantly reducing the chance garbage bins). Understanding the of infection13. This change to the nature of the problem is important Cairncross, S., Muller, R., and environment (i.e., making clean in determining which approach has Zagaria, N. (2002). water available) proved to be key in the best chance of success. Dracunculiasis (Guinea Worm eliminating the disease. Disease) and Education, safety messages the Eradication While this is an oversimplified and raising awareness Initiative. Clinical description of the complex and Microbiology Reviews, 223-246. multifaceted approach that occurred Education and awareness-raising over 30 years, it highlights what can campaigns are often the first and be accomplished when principles of only tools tried when attempting behavior change are at the core of a to influence behavior. In general,

2-10 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS This tip card from the early 1900s was likely ineffective in changing the crossing habits of people since it relied solely on providing information.

the goal of such campaigns is to example: does simply knowing that communicate information with the you should floss convince you to assumption that once the audience floss regularly? is aware of the information, they Consider the effect of an educational will then act in the desired manner. campaign on Guinea worm disease. In other words, educational Would an educational or awareness campaigns appeal to the deliberative raising campaign be enough to system and assume that human produce lasting and consistent behavior is usually a product of behavior change? On the one hand, rational thought. Because of this, there was a lack of knowledge information alone almost never about the disease among those works. However, information affected, especially about how the can be helpful as part of a more disease was transmitted. However, comprehensive program. this education cannot influence Far too often information-based the additional — and likely more approaches are used in isolation, important — factors contributing to without careful consideration the problem. For example, education of whether the problem can be will not improve the availability effectively addressed through of clean drinking water or access raising awareness alone. Is the to alternative medical resources, information new to the audience? nor will it provide the financial Is it likely that knowing this resources necessary to increase information will produce the desired access to either. Thus, an education outcome? To draw from a previous campaign, on its own, would not

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-11

FIGURE 2-4: Example of shopping center and bus stop

have been a successful tactic. What behavior is being targeted? Instead, health officials needed a Crossing Elm Street midblock. more comprehensive approach. What are the other factors influencing The same considerations can be this behavior? applied to road safety problems. Consider the following example: JJ Convenience – Crossing mid- block provides a more direct Your city manager notices an route to the bus stop. People increase in pedestrian crashes coming from the shopping center following the placement of a new are likely carrying shopping bus stop on Elm Street, a busy bags, which could be difficult to multi-lane road without a median. carry long distances. The bus stop is located in the middle of the block across from a large JJ Previous experience – It is likely shopping center (Figure 2-4). The that people have successfully nearby intersections on either side crossed similar streets (or even are signalized and have street lights, the same street) in this manner crosswalks and pedestrian signals. many other times, so their The intersection and crosswalks limited previous experience meet all applicable design standards suggests this is a safe option. (we and are therefore nominally safe. say limited experience because Although city engineers intended people not likely to be aware of that people would cross the street the location’s crash history). at the intersections, observations JJ Time pressure – Buses run on a show that many people are crossing schedule, and people may want mid-block from the shopping to cross as quickly as possible to center to the bus stop, resulting in be sure they catch the next bus. frequent conflicts with vehicles. The city wants to improve safety in this Is an educational or awareness area and has decided to undertake a raising campaign targeting this media campaign encouraging people behavior likely to be effective? No. to cross only at crosswalks. In all likelihood, people who are

2-12 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS crossing the street in this spot know can’t change the person, change the there are crosswalks at the nearby world so that the person will follow. intersections. They are crossing the We know that people are crossing street here because it is easier and Elm Street mid-block because it is more convenient, and their previous quicker, easier and more convenient experiences tell them they will be than using the crosswalks at the successful. Additional information is unlikely to alter these factors; nearby intersections. Information or therefore an informational or awareness campaigns are unlikely awareness-raising campaign alone to influence this behavior because will not be effective. However, that the behavior is not due to a lack of does not mean that all hope is lost. awareness or information. Instead, Improving the safety of pedestrians we need to change the environment crossing Elm Street is still possible so that the pedestrians are no longer with the right approach. crossing somewhere other than a marked crosswalk. Changing the environment Possible changes to the environment A preferred alternative to education include building a wall or putting is changing the environment. up a fence to deter people from We know that people act based crossing at the mid-block, or on information gleaned from the building a pedestrian bridge to keep world around them, and that most people out of the flow of traffic. of our behavior is unconscious and These solutions might be cost driven by the intuitive system. By prohibitive, and research shows that 14 changing the environment, people most pedestrians will still cross a Moore, R.L., Older, can be moved towards the behavior street at ground level even when a S.J., Pedestrians of interest. In other words – if you pedestrian bridge is available.14,15 and Motors are Compatible in Today’s World. Traffic Engineering, Institute of Transportation Engineers, Washington, DC, September, 1965.

15

Rasanen, M, T. Lajunen, F. Alticafarbay, and C. Aydin, Pedestrian Self Reports of Factors Influencing the Use of Pedestrian Bridges, Accident Analysis and Prevention, 39, pp. 969-973, 2007.

FIGURE 2-5: Pedestrian hybrid beacon (Source: pedbikeimages.org/Mike Cynecki)

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-13 Another approach would be to move the bus stop closer to the existing crosswalks, assuming people will choose to cross at the crosswalk since it is now more convenient. Finally, another alternative would be to install a marked crosswalk with a pedestrian hybrid beacon close to the area where people are crossing (Figure 2-5). This solution recognizes the factors influencing people’s behavior and provides an alternative that would Seat belt usage in improve safety and be acceptable to the United States pedestrians. Seat belt use in the United States has 16 We know that people respond a remarkably similar, though opposite Tison, J. & Williams, in predictable ways to their trajectory to that of Guinea worm A.F. (2012). environments — far more than to disease. Though seatbelts were required Analyzing the First in U.S. vehicles starting in the late internal conditions like attitudes Years of the Click It or 1960s, use of this equipment was low. Ticket Mobilizations and personality. Environment can (DOT HS 811 232). Observational surveys from the early to 16 Washington, D.C.: include both the physical (built) mid-1980s found use of 5-14 percent. National Highway environment and things like By 2015, however, observed seatbelt use Traffic Safety policies, laws and social norms. had climbed to 88.5 percent.17 Administration. Let’s revisit the speeding example As with Guinea worm disease, no single from earlier in the unit (Figure 2-1). effort was responsible for increasing seat Although the posted speed limit belt use in the United States. Instead, 17 is 35 mph, in reality many people efforts that focused on changing the environment (e.g., enactment of seat belt Pickrell, T. M., & Li, drive much faster than that. What and child passenger safety laws) were R. (2016, February). might we do to get drivers to slow Seat Belt Use in coupled with high visibility enforcement 2015—Overall Results down on this road? One option is (e.g., Click-it-or-Ticket). Education played (Traffic Safety to post additional speed limit signs a role in these efforts, but not in raising Facts Research Note. Report No. or run local PSAs about the dangers awareness for the dangers of not wearing DOT HS 812 243). of speeding. However, consider seat belts. Rather, education was needed Washington, DC: whether informational signs would to inform people that belt use is required National Highway and, especially, to create the perception Traffic Safety result in lower speeds. Are drivers among the driving public that police Administration. speeding because they are not aware were actively enforcing seat belt laws. of the speed limit? Are drivers unaware of the potential dangers of high speeds? The answer to both of road users respond. In the previous speeding example, the overall these questions is “not likely.” design of the road has already been One example of environmental established, but the lanes could be change to reduce driver speed is the narrowed or even reduced to one use of traffic calming measures. in each direction to communicate, Features such as speed humps and “This is a road where you should mini roundabouts are examples of drive slower.” Traffic calming physical alterations to the driving addresses the intuitive system in that environment that influence how it results in drivers slowing down

2-14 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS without being aware of doing so.18 and the many factors that influence 18 behavior is crucial to solving Consider behavior in safety problems. Lewis-Evans, B. & Charlton, S.G. addressing travel safety (2006), Explicit and People generally don’t simply implicit processes Making strides in road safety is do what they are told to do. in behavioural possible. However, as with the adaptation to Information and awareness-raising road width. near eradication of Guinea worm Accident Analysis disease, significant achievements campaigns are often the first tools & Prevention, 38, 610-617. will not happen overnight. When used in efforts to influence behavior. implementing a program or However, these approaches are intervention aimed at changing too often adopted without careful behavior, it is important to consideration of whether the remember that any road safety issue behavior is likely to be changed is likely the result of a combination merely with information (which the of factors. Consequently, it is public often already has). unlikely that any one program or The environment heavily influences intervention will completely solve the problem. However, combining human behaviors. We are constantly behavioral science principles with processing information and engineering design can help to adjusting our behaviors accordingly. produce significant advances. Most of this behavior is unconscious See Unit 4 for a discussion of and driven by the intuitive system. how to identify and address Changing behavior requires road safety problems. an understanding of all Conclusion influencing factors.

In short, human behavior Before attempting to influence is extraordinarily complex. behavior, it is essential to identify Consequently, it is difficult to and understand the important influence. Simple, common sense factors influencing a behavior. approaches like merely raising Targeting a behavior without a full awareness or otherwise providing understanding of these factors will information about an issue virtually almost certainly be unsuccessful. never succeed. Because so much of what we do is Humans are not exclusively intuitive and heavily influenced by logical, rational beings. our environment, we sometimes respond to the transportation We often assume human behavior is controlled by a logical deliberative infrastructure in ways not process when, in fact, most anticipated by the engineers who behaviors are a result of an intuitive designed it. By changing the 19 process. Many factors influence environment, people can be nudged towards the behavior of interest.19 Thaler, R.H., and behavior including education, Sunstein, C.R. emotions, cultural norms, In other words, if you can’t change Nudge: Improving the person (and you usually can’t!), Decisions About religious beliefs, social pressures, Health, Wealth, and convenience, habits and finances. change the world so that the person Happiness. Understanding human behavior will follow.

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-15 Bus stop with crossing pedestrians in Portland, Ore. (Source: pedbikeimages.org/Laura Sandt)

The transportation system is infrastructure) and the user when designed, built, maintained, governed trying to understand behavior and used by humans. and develop solutions to safety problems. Using the term human factors to refer exclusively to the In sum, significant advances in road user perspective (i.e., drivers, safety are possible, but changes pedestrians, etc.) can easily convey will not happen overnight. Human an oversimplified notion of the role behavior is not easy to change. of humans in the transportation With thoughtful, comprehensive system. From design to use, humans approaches that take into account play a role in every step of the an understanding of human transportation system. In that sense, behavior and the environment the entire transportation system in which people live, we can is a product of human factors. For develop programs, policies and that reason, safety professionals countermeasures that have a better must consider both the role of the chance of significantly improving environment (e.g., transportation road safety.

EXERCISES

JJ CREATE a causal diagram to model the JJ Using the causal diagrams from behavior(s) and environmental factor(s) exercise 1, IDENTIFY the weak links that contribute to the following. in the causal chain and describe an intervention aimed at changing the JJ The flu target behavior(s). JJ Unhelmeted motorcyclist fatalities

2-16 UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY ROAD SAFETY FUNDAMENTALS THIS PAGE INTENTIONALLY LEFT BLANK

ROAD SAFETY FUNDAMENTALS UNIT 2: HUMAN BEHAVIOR AND ROAD SAFETY 2-17 UNIT 3 Measuring Safety

LEARNING OBJECTIVES

After reading the chapters and completing JJ UNDERSTAND the challenges exercises in Unit 3, the reader will be able to: and accuracy of data

JJ DESCRIBE why measuring safety JJ SELECT data for different is important road safety objectives

JJ IDENTIFY the different types of available data

3-b UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS CHAPTER 7 MEASURING SAFETY Importance of Safety Data

Good quality safety data are the core Devices (MUTCD) and A Policy on of any successful effort to improve Geometric Design of Highway and road safety. Local, State, and Federal Streets, also known as the Green agencies use crash data as well as Book1,2. However, most of these 1 roadway, vehicle, driver history, standards are engineering based emergency response, hospital, and (i.e., nominal safety as discussed Manual on Uniform enforcement data to improve road in Unit 1), and were not necessarily Traffic Control Devices (MUTCD), safety. All of these data sources can based on an evaluation of actual Federal Highway be used, in isolation or jointly, to road safety performance. Presently, Administration, 2009. produce projects, programs, and transportation professionals use guide policies that reduce injuries safety data (such as crash data, road characteristics, and traffic and save lives. These types of data 2 are collectively categorized as safety volume) to evaluate road safety data in this book. performance and inform their A Policy on Geometric Design decisions. This substantive approach of Highways and Safety professionals in many challenges professionals to quantify Streets, American disciplines – highway design, Associations of the expected consequences and transportation planning, State Highway outcomes of safety strategies in real Transportation operations, road maintenance, measurements, such as the expected Officials, 6th law enforcement, education, edition, 2011. number of crashes, injuries, emergency response services, and fatalities. policy makers, infrastructure program management, road safety The selection of road safety management, and public health – measures and treatments can use safety data to identify problem benefit from an understanding of areas, select countermeasures, and the intricacies and limitations of monitor countermeasure impact. safety data. This unit presents many kinds of safety data, explores the Road safety management and current process used to collect data, project development has become and discusses the impact that these increasingly data-driven and processes have on data quality (i.e., evidence-based. This approach accuracy and reliability). The unit to road safety emphasizes safety also discusses ways to improve data performance (i.e., number of quality and analysis. crashes), rather than solely adhering to engineering standards, personal Relating Nominal and experience, beliefs, and intuition. Substantive Safety to Data For example, in the past, road improvements were considered The concepts of nominal and “safe” if the improvements met substantive safety were first the standards contained in the introduced in Unit 1 of this textbook. Manual on Uniform Traffic Control Nominal safety refers to whether

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-1 or not a design (or design element) Use of Safety Data in Road meets minimum design criteria Safety Management based on national or State standards and guidance documents, such as Data are integral to safety decision the AASHTO Green Book or the making, both in prioritizing MUTCD. Substantive safety refers to investments and in identifying the actual safety performance, such analyzing the most effective as expected number of collisions by techniques and interventions. type and severity on a road. The more comprehensive and accurate the data, the better the The contrast of these concepts is resulting decisions. Understanding directly linked to this discussion of contributing factors to crashes and safety data. To determine if a road how best to implement potential is nominally safe we do not need countermeasures is complex, and safety data; we only need to know if it may involve a variety of agencies all design standards were followed. and historical data challenges. However, we need high quality Because of this complexity, both safety data and data analysis to accurate data and high quality data determine if a road is substantively analysis is necessary for road safety safe. Typically, the analysis includes management. A great database is estimating the expected number of only as useful as the analysis and crashes and comparing it against the application of that data. Table 3-1 road’s actual safety performance. explores the relationship between More information on safety analysis data quality and data analysis quality is presented in Unit 4, Solving Safety and shows why agencies should Problems. strive to improve both of these areas.

3-2 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS HIGH QUALITY ANALYSIS LOW QUALITY ANALYSIS

BEST CASE MISSED OPPORTUNITY

The agency is likely to reach the best The agency needs to invest in high safety decisions. Analysts are aware quality analysis. Otherwise, the agency of data capabilities and limitations. has wasted money in databases This is the most expensive to achieve, that are not being utilized to their due to the need for good data and potential. Good data with poor training on how to conduct analyses. analysis will lead to poor decisions. HIGH QUALITY QUALITY HIGH DATA

PROMISING WORST CASE

A robust analysis that recognizes Poor data and poor analysis will lead the limitations of the data can to bad decisions. The agency may be still produce useful results. better off relying on judgment. The agency should focus on improving data quality. LOW QUALITY QUALITY LOW DATA

TABLE 3-1: Data and Analysis Quality Comparison

Crash data analysis using how specific planning guidance, quantifiable metrics and design proposals, or engineering scientifically defensible methods can countermeasures can save lives. help decision makers improve road safety by reducing more injuries and Safety professionals could seek to saving more lives at a lower cost. improve safety by relying merely on Accurate crash data help determine their gut judgment. The results of crash and severity trends, such as such an approach, however, would increases or decreases in certain be quite unreliable. As shown in types of crashes. Data also help Table 3-1, safety professionals can safety professionals pinpoint high improve their decision making crash locations and identify high- process by using high quality data risk users, such as younger drivers, together with robust analysis older drivers, impaired drivers, processes. This unit will focus on and motorcyclists. Examining the data itself. The use of the data in the characteristics of crashes safety management is presented and allows road safety professionals to discussed in Unit 4. identify contributing crash factors related to roadway environment, Good quality safety data and design, or behavioral adaptations. analysis are the keys to identifying This type of analysis will lead real safety issues on roads and to a more effective selection of evaluating the best methods for countermeasures that will reduce improving safety. The following future crash occurrences or crash chapters provide an overview of severity. Planners and engineers can different types of safety data and of use crash data to show quantitative ways in which agencies can improve information to decision makers on the quality of their data.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-3 CHAPTER 8 MEASURING SAFETY Types of Safety Data

As highway safety analysis methods continue to evolve, it Chicago’s Use of Injury Data is equally important to focus on to Benchmark Safety Goals quality data to conduct these safety and Progress analyses. Transportation agencies Chicago DOT completed a can and should incorporate road comprehensive pedestrian crash characteristics, traffic volume, and analysis in 2011 to inform the citywide Chicago Pedestrian Plan. This analysis enforcement and citation data, evaluated various crash types, and other information into their contributing environmental factors, and safety analysis processes. This will different age groups using the Illinois enable them to better identify safety Department of Transportation crash problems and prescribe solutions data files. The findings present crash that improve safety and make more density citywide, by ward, and around schools. The data also highlighted efficient use of safety funds. key crash conditions and served as a benchmark for measuring the City of Single sources of safety data also Chicago’s road safety goals. do not give a complete picture of the safety risks on our roads. Reference: City of Chicago 2011 Pedestrian For example, using crash data by Crash Analysis, Summary Report, Chicago Department of Transportation, itself leaves safety practitioners Accessed September 2016 at https://www. with purely reactive approaches— cityofchicago.org/city/en/depts/cdot/supp_ identifying locations where info/2011_pedestrian_crashanalysis.html crashes have already happened. By combining crash data with other types of data, more details or geospatial position. These data begin to emerge. For example, by should also have the ability to be combining crash data and detailed linked to the State’s other road road inventory information, safety safety databases, including citation practitioners can develop a more data or injury surveillance systems. in-depth understanding of the road Additionally, commercial motor attributes that contribute to crash Roadway vehicle data could also be linked risk. This will allow them to adopt elements based upon common data elements a proactive approach, seeking out involved in crashes and inspections. Physical those factors associated with a high Not all types of safety data are features of the risk of crashes and addressing sites road such as available or used by all practitioners. that share those “elements” before a travel lanes, Safety data exist in distinct crash occurs. shoulder width, databases that are maintained by pavement condition, Crash, roadway, and traffic data different agencies and often are and roadside should be integrated or combined accessible only to those agencies. characteristics using common or “linking” One role for safety professionals is reference systems, such as mileposts to bring together safety databases

3-4 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS and analyze them using logical and of time it often takes for crashes to statistically robust processes. be entered into a database. Crash data is also the primary measure Safety data can be categorized into of effectiveness for safety efforts, two groups based on criteria of core since the goal is to decrease crash data needs for safety evaluations, occurrences and lower the severity of data availability, accuracy, and crashes that do occur. Crash records usefulness to safety practitioners typically provide details on events and researchers. Some safety data leading to the crash, vehicles, and are used often and are critical to people involved in crashes, as well as safety analysis for many agencies. the consequences of crashes, such as Other safety data are used less fatalities, injuries, property damage, often but can be supplemental to and citations. specific safety analyses. This chapter provides general information on Data collection process safety data in these two groups: Crash data collection begins when a Critical data State highway patrol trooper or local police officer arrives at the crash JJ Crashes scene. The officer completes a crash JJ Traffic volume report, documenting the specifics JJ Road characteristics of the crash. While the specifics Supplemental data and level of detail of the crash data vary from State to State, in general, JJ Conflicts and the most basic crash data consist of avoidance maneuvers where and when the crash occurred, JJ Injury surveillance and what type of crash it was, and who emergency medical systems was involved. The specific data JJ Driver history collected on crashes is determined JJ Vehicle registrations by State agencies, local government JJ Citations and enforcement agencies, and often a coalition of law enforcement agencies. The exact data JJ Naturalistic fields and coding differ from State to JJ Driving simulator State. The level of detail in a crash JJ Public opinion report may also differ by the severity JJ Behavioral observation of a crash. For instance, in some Crash Data States property damage only crashes (PDO) are self-reported and, thus, Description often have less information than injury crashes, which are reported by Crash data is the most widely used law enforcement officers. type of safety data, and it is essential in road safety analysis. Crashes States also differ in the threshold are currently viewed as the most of what is required for a crash to be objective and reliable measurements reported. Reporting of crashes can of road safety. However, there vary by threshold requirements, such are challenges with crash data, as “only injury crashes” or “PDO such as human error in reporting, crashes over an estimated $2,000 unreported crashes, and the length in damage.” These thresholds are

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-5 B Crash date and time: The date (year, month, and day) and time (00:00-23:59) when the crash occurred. A I Case identifier: The unique identifier Roadway C within a given year that identifies a surface Crash county: The county or equivalent specific crash within a State. conditions: The entity where the crash physically occurred. roadway surface condition at the time and place of a crash. A

B,C J Contributing I,J circumstances, D,E,F,G,H road: Apparent condition of the road that may have contributed D to the crash. Crash classification: Used to identify K,L,M Driver ownership of the land where the crash information occurred and identify the characteristics of the crash with respect to its location on or K Weather off a trafficway. conditions: The prevailing E atmospheric Crash city/place: City/place (political conditions that jurisdiction) in which the crash occurred. existed at the time of the Vehicle information crash. F Type of intersection: An intersection consists of two or more roadways that intersect at the same level. L Contributing circumstances, environment: G Relation to junction: The coding of Apparent this data element is based on the location environmental of the first harmful event of the crash. It conditions identifies the crash’s location with respect which may have to presence in a junction or proximity to contributed to components typically associated with the crash. junction or interchange areas.

M H Light Crash location: The exact location on conditions: the road where the first harmful event The type/level of of the crash occurred. It is best if this light that existed information includes a geolocation based at the time of on a Geographic Information System the motor (GIS) or Linear Referencing System (LRS) vehicle crash. location coordinates.

3-6 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS N O R Manner of crash/collision impact: The First harmful event: The first injury or Work zone- identification of the manner in which two damage-producing event that related: A crash motor vehicles in transport initially came characterizes the crash type. that occurs in together without regard to the direction or related to a of force. This data element refers only construction, to crashes where the first harmful event P maintenance, or Location of first harmful event relative involves a collision between two motor utility work zone, to the trafficway: The location of the first vehicles in transport. whether or not harmful event as it relates to its position workers were within or outside the trafficway. actually present at the time of the crash. Work zone-related R crashes may also include those involving motor vehicles slowed N,O,P or stopped Q because of the work zone, even if the first harmful event occurred before the first Q School bus-related: Indicates whether warning sign. a school bus or motor vehicle functioning as a school bus for a school-related purpose is involved in the crash. The Crash sketch/ school bus, with or without a passenger diagram on board, must be directly involved as a contact motor vehicle or indirectly involved as a non-contact motor vehicle (children struck when boarding or alighting from the school bus, two vehicles colliding as the result of the stopped school bus, etc.).

Crash narrative

S Source of information: Affiliation of the person completing the crash report. S

FIGURE 3-1 (above, left): Data elements on a crash report form. (Source: North Carolina DOT)

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-7 unrelated to the number of crashes National Highway Traffic Safety that are actually occurring on a road, Administration’s (NHTSA’s) Fatality but the reported numbers could look Analysis Reporting Systems (FARS). quite different. Changes to the crash The time between the crash reporting thresholds can happen occurrence and the availability abruptly and may significantly affect of the crash data from the State the crash data. Consider how the crash database varies and typically safety of a road, based on reported depends on the type of crash crashes, would appear in the years reporting system and the State before and after a crash reporting and local government capabilities. threshold change from $1,000 to This time period between crash $4,000. You would expect to see occurrence and the report’s fewer reported crashes after the availability for analysis defines the change, since crashes with damage timeliness of the crash data. While below $4,000 would no longer be some agencies can provide complete reported, even though there may data with a very short turnaround be no real change in the number of (i.e., less than a month), others take crashes occurring. significantly longer (i.e., up to two After the crash investigation is years) due to backlogs and personnel completed by the officer for the shortages. Agencies who have the investigating agency, it usually majority of their crashes reported undergoes an internal quality review. electronically from law enforcement Passing the internal review, the typically have shorter turnarounds crash report is sent to the State crash on the crash data. database. In some cases, the data is Common data elements transmitted electronically, while in other cases the State agency receives Common data elements for crash a paper copy of the crash report. data include information on date, location, injury severity, types of The agency that maintains crash vehicles, and characteristics of data for the State may be the State persons involved. Crash narratives department of transportation and diagrams are typically found in (DOT), the department of motor the original crash reports, though vehicles (DMV), or a State law generally not in the crash database. enforcement agency. This agency Narratives and diagrams are most will in turn make the data available useful when the safety professional to various other agencies. Federal, desires to know the exact location State, and local governments, as of the crash, such as the particular well as metropolitan planning approach of an intersection. organizations, advocacy groups, auto and insurance industries, and private NHTSA developed the Model consultants request crash data to Minimum Uniform Crash Criteria conduct various transportation (MMUCC) in 1998 as a model set planning activities and analysis. of data elements that should The agency maintaining the be collected to enable safety data may provide raw or filtered professionals to conduct data-driven datasets to local agencies and to analyses. States are encouraged national databases, such as the to adopt MMUCC standards,

3-8 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS though they are not required to data. For example, by combining match these recommendations. road characteristics with crash MMUCC, currently in its fourth data, safety professionals are able edition, recommends the crash data to identify road elements that may elements listed below. Chapter 9 lead to higher frequency or injury presents further information on severity of crashes, and therefore MMUCC on page 3-30. develop a systemic approach to Data sources and custodians reduce that crash risk at many of the locations that have those risk Crash details may be available from elements. Using traffic volume, different sources or systems. State agencies can calculate crash rates agencies and institutions typically (e.g., crashes per road vehicle) to maintain the State crash database. better identify locations requiring These include State departments safety improvements. of transportation, departments of motor vehicles, departments of Caution on the use of crash rates public safety, or in some cases, State universities under contract to a Crash rate calculation (crashes per specific department. Local agencies, amount of traffic) is a simplistic measure that may be useful when such as cities or metropolitan comparing sites with similar planning organizations, may also characteristics and traffic volumes. maintain their own crash databases However, the relationship between within local record management crashes and volume is not linear and systems. These local systems can therefore lead to wrong conclusions are most frequently housed by if that assumption is made when considering volume increases on a road the local police, public works, or or comparing roads of different types. transportation departments. Unit 4 discusses how an analyst can use Transportation safety applications safety performance functions to avoid this error. Crash data serve as the primary observable measure of safety Data challenges and gaps (or lack thereof) on the road. Transportation professionals can use Some of the most common issues crash data to analyze a single crash, found in crash reporting include a specific site, an entire corridor, incomplete data (for example a or a large area, such as in regional driver’s blood alcohol content is or Statewide planning. Crash data often missing), delays in entering can be used to provide guidance to the data into databases, inaccurate transportation decision makers and crash locations, and wrongly to guide the formation of safety assigned fault and wrong choice of legislation. crash type. Some of these issues can be fixed by training police officers Coordination or integration with and those who enter the data into other data sets the database, as well as by using In transportation departments, technology checks in data collection. other data elements frequently used Agencies should periodically conduct along with crash data include road independent quality checks on the characteristics and traffic volume accuracy and reliability of their data.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-9 Challenges with the Use of Crash Data to Systemically Identify High Risk Locations

The Oregon DOT identified pedestrian and of road information (e.g., bicyclist and bicycle crashes as one of its primary focus pedestrian volumes, the presence of areas for infrastructure funding. While crosswalks, turn lanes, driveway activity, pedestrians and bicyclists account for more and sight distances). While the lack of than 15% of all traffic fatalities statewide, these data does not preclude such an the locations of serious injuries and analysis, it does reduce the certainty of the fatalities appear to be random. Therefore, findings. An additional benefit from this in 2013, ODOT set out to develop a effort is that it has helped ODOT identify program that focuses the limited available current data deficiencies which ODOT is funding for infrastructure countermeasures currently working to fix. on locations with the greatest crash potential. In order to identify these higher- Reference: Pedestrian and Bicycle Safety risk locations, ODOT is working to discover Implementation Plan, Oregon Department behavioral patterns and road conditions of Transportation, February 2014. Accessed that lead to pedestrian and bicycle crashes. September 2016 at https://www.oregon.gov/ While a promising approach, this analysis ODOT/HWY/TRAFFIC-ROADWAY/docs/ is constrained by the limited availability pdf/13452_report_final_partsA+B.pdf

Traffic Volume Data AADT is the average number of vehicles passing through a segment Description from both directions of the mainline Traffic volume data indicates how route for all days of a specified many road users travel on a road or year. As AADT requires continuous through an intersection. The most year-round counting, these data prevalent type of volume data is are often unavailable for many road segments. In these cases, ADT is a count of daily use by motorized used to estimate AADT by using vehicle traffic. This type of traffic shorter duration counts of that road volume data can be measured and then adjusting those volumes in many ways depending on the by daily and seasonal factors. Other intended use. Volume measurements data used for crash analysis include include: turning movement counts and JJ Annual average TEV at intersections and VMT on a daily traffic (AADT) road segment, which is a measure JJ Average daily traffic (ADT) of segment length and traffic volume. VMT are useful for highway JJ Total entering vehicles (TEV) planning and management, and a for intersections common measure of road use. Along JJ Turning movement counts with other data, VMT is often used JJ Vehicle miles traveled (VMT) to estimate congestion, air quality, JJ Pedestrian counts and expected gas tax revenues, and JJ Bicyclist counts can serve as a proxy for the level of JJ Percentage of traffic for specific a region’s economic activity. Volume data is also occasionally collected vehicle types (e.g., heavy trucks for bicyclists and pedestrians at road or motorcycles) segments and crossing locations.

3-10 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Data collection process What’s the difference between Volume data can be collected ADT and AADT? automatically or manually. Vehicle volume data is typically collected Short term traffic counts are typically collected at a location for a 12-, 18-, or using automated counters, 24-hour period. Average Daily Traffic such as magnetic induction (ADT) is the count of traffic calculated loops, pneumatic tube counters, to reflect the 24-hour (daily) volume microwave, radar, or video detection. of the date it was collected. The These automated counters can also Annual Average Daily Traffic (AADT) is be configured to classify vehicles calculated for an entire year from the and produce counts by vehicle ADT by adjusting that simple average traffic volume to take into account the type (e.g., trucks, single passenger different travel patterns that occur vehicles, etc.). For shorter durations during short duration count periods. For or occasional counts, transportation example, a summer traffic count taken agencies use manual traffic counts in a beach vacation town would need performed by observers, either in to be adjusted downward to reflect the the field or through video cameras. average traffic volume for the year, since traffic would be much higher in Manual counting is also used often the summertime. for bicyclist or pedestrian counts, although there are a number of additional technologies, such as best practices and provides guidance infrared beams, that can be used to highway agencies in traffic to collect non-motorized volume volume data collection, analysis, data. These manual counts can range and reporting3. The TMG presents in length from one-hour counts recommendations to improve to full-day counts, depending on and advance current programs 3 the agency’s needs and practices. with a view towards the future of Traffic Monitoring Fitness tracking apps may also traffic monitoring. Traffic data is Guide, Federal provide additional information used to assess current and past Highway to jurisdictions regarding where Administration, performance and to predict future Office of Highway bicyclist and pedestrian activity is performance. Some States are Policy Information, occurring. Some care is needed when utilizing traffic data from intelligent September 2013. using these data due to the self- transportation systems (ITS) to selection bias present from users support coordination of planning having to opt-in to the tracking and operations functions at the and only using for specific types of Federal and State levels. activities (e.g., fitness cycling rather than commuting). Common data elements

Each State has its own traffic data Volume data must include the collection needs, priorities, budget, counted volume, location, date, and and geographic and organizational duration of the count. Depending constraints. These differences on the method used, the volume cause agencies to select different data may also contain information equipment for data collection, use on vehicle classification, speed, different data collection plans, or weight; lane position; weather; and emphasize different data and directional factors. From these reporting outputs. The FHWA Traffic data, transportation professionals Monitoring Guide (TMG) highlights can calculate the average number of

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-11 vehicles that traveled each segment of estimates of total distance traveled. road and daily vehicle miles traveled Annual traffic volumes are also for specific groups of facilities, essential in network screening, vehicle types, and vehicle speeds. diagnosis, and the selection of countermeasures (see further Data sources and custodians presentation of these processes in State highway agencies collect Unit 4). When selecting appropriate and maintain traffic volume data crash modification factors (CMFs) for State-controlled roads. These to estimate the benefit of potential data are shared with the U.S. countermeasures, a safety Department of Transportation in practitioner must use traffic volumes order to monitor road usage and to confirm that the CMFs are suitable safety trends. Local jurisdictions for the site in consideration. also collect and maintain traffic Coordination or integration with volume data; the scope, consistency, other data sets and quality of these data varies by jurisdiction. Other data elements frequently used with traffic volume data Transportation safety applications in safety applications include Agencies use volume data to support road characteristic inventories activities in design, maintenance, and crash data. For example, an operations, safety, environmental agency that uses traffic volume and analysis, finance, engineering, crashes together can identify sites economics, and performance with highest potential for safety management. For instance, total improvements and target specific traffic volume estimates or forecasts crash types. This allows them to on a section of road are used to better identify and prioritize locations generate State and nationwide for safety improvements.

Spatial Data and Road Safety

Many of the types of data presented in this chapter can be stored in a spatial format and displayed in a GIS. GIS is a particularly powerful tool designed to store, manipulate, analyze, and visualize data that is linked to a location. This makes it valuable to highway safety practitioners who can use a common referencing system for much of their highway data and link it together in GIS. For example, a single GIS database can contain road attributes, such as number of lanes, pavement condition, This GIS map displays signalized and lighting; crash information; and intersections as squares and crashes traffic volumes. This information can then as dots and allows the analyst to easily be used to analyze crash hotspots and identify crashes occurring within 150 feet trends, such as multi-vehicle crashes in the of a signalized intersection (denoted by vicinity of signalized intersections. circular areas around each intersection).

3-12 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Data challenges and gaps

One of the biggest challenges in collecting accurate volume data is implementing a quality assurance process to ensure that counts are accurately recorded. Traffic volume for most roads is also based on sampling, which leads to estimates of volume on much of the road. As technology continues to develop and become more prevalent on our roads and in our vehicles, the accuracy will improve considerably. Additionally, pedestrian and bicyclist counts are more susceptible to higher variability FIGURE 3-2: This image from the FHWA due to their lower volumes; Model Inventory of Roadway Elements thus, longer count durations and (v. 1.0) illustrates roadway elements. additional locations are required for accurate data applications. Ranging (LIDAR) technology. Some States find it more cost effective to Road Characteristics Data purchase these data from third party Description providers.

Road characteristics data is also Common data elements referred to as road inventory data. Transportation agencies typically The most basic road characteristics collect those road characteristics data typically includes road name or that they need or can be collected route number, road classification, based on the available funds. Road location coordinates, number of characteristics are collected for many lanes, lane width, shoulder width, different purposes, such as road and median type. Intersection maintenance and improvement characteristics typically include projects. Given that States have road names, area type, location different priorities and funding coordinates, traffic control, and structures, the elements of road lane configurations. The collection characteristics data is not the of these data elements supports same from State to State or among an enhanced safety analysis and local agencies. investment decision making when combined with other datasets, such To provide guidance on road as crash information. characteristics that are the most needed for safety analysis, the FHWA Data collection process developed the Model Inventory of Road characteristics data can be Roadway Elements (MIRE). MIRE collected through several methods provides a recommended (but not including photo or video logs, field required) list of road characteristics surveys, aerial surveys, integrated elements specifically for safety GIS and global positioning systems analysis. The elements are divided (GPS) mapping, and vehicle- into the categories shown in Table mounted Light Detection and 3-2. Chapter 9 presents further

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-13 information on MIRE on page 3-32. crossings as part of the Federal Railroad Administration’s Railroad Data sources and custodians Grade Crossing Inventory. These Road characteristics data are databases usually can be linked to collected at both the local and the Statewide road inventory. Statewide levels. At the local level, Transportation safety applications having data on details, such as traffic control devices, sidewalks, or Road safety professionals can the number of travel lanes, can be use road characteristics data to beneficial for safety evaluations and access data about the physical safety project prioritization. These characteristics of crash sites data are maintained by the city or by or other priority sites. Road a higher level agency such as a MPO. characteristics data is essential for network screening, development State road characteristics data or calibration of crash prediction include physical road attributes, models, and related applications. traffic control devices, rail grade These data are also valuable on the crossings, and structures, such large scale level to estimate where as bridges and tunnels. Each crashes are expected to occur on the State highway agency, some system. local transportation and public Coordination with other data sets works departments, and regional planning agencies collect and Road characteristics data can be maintain road characteristics data. linked with crash and volume data to In addition, most States also have improve safety analysis and problem supplemental inventory data for identification. Combining datasets in bridges as part of the National this way allows safety professionals Bridge Inventory and railroad grade to identify areas with a high

CATEGORY EXAMPLES OF MIRE DATA ELEMENTS

Roadway Segment Roadway classification Paved surface characteristics Number and type of travel lanes Shoulder, median, and roadside descriptors Pedestrian and bicyclist facilities Traffic volumes

Roadway Alignment Curve and grade information

Roadway Junction Traffic control devices Intersection features Interchange and ramp descriptors

TABLE 3-2: Categories of MIRE Elements

3-14 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS VOLUME DATA

Determine roortional Calculate issues from specific redicted crashes ehicle tyes rom saety erormance Calculate unctions crash rates Deelo saety erormance unctions or redicting crashes

Prioritie maintenance CRASH DATA actiities ROAD DATA Prioritie systemic imroements Determine ris actors

FIGURE 3-3: Using Safety Data Together potential for safety improvements consuming and expensive process. (by means of a network screening Data collection that is done only process) and identify appropriate for part of a road network results countermeasures. However, the in gaps in inventories of road road characteristics data must share features such as the location of a common reference system with guardrails, shoulder widths, and the crash and volume data in order rumble strips. Transportation to link them together. The most agencies are continually looking for common methods of linking road newer technologies to streamline data with crash or volume data use the collection of this detailed data. a linear referencing system, such as Also, it is more common for road routes and mileposts, or a spatial characteristics data to be fuller referencing system, where all files and more detailed for State system share the same coordinate system. roads compared to local roads, Data challenges and gaps since local agencies typically have less funding, fewer staff, and less Collecting accurate road general prioritization for collecting characteristics data can be a time- road characteristics data.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-15 Observing interactions between road users, like these drivers and crossing pedestrians, can be a good way to gain supplemental data about safety effects.

Supplemental Safety Data on road safety. These other measures of safety are referred to In addition to the critical as surrogate measures. They occur transportation safety datasets more frequently than actual crashes (crashes, road characteristics, and and therefore enable agencies to traffic volume), there are many identify safety risks more quickly other datasets that can be used and and in a proactive manner (i.e., combined to conduct additional before the crash occurs). However, types of evaluations on the by their nature of being surrogates, effectiveness of programs, human there is potential for inaccuracy in behaviors and safe decision making, determining which types of conflicts and public opinions. are good indicators of crashes. Conflicts, Avoidance Maneuvers, Surrogate safety data is collected and Other Interactions by in-field observers or through Observing conflicts between road recordings that capture the users, avoidance maneuvers, such as behaviors and interactions of road swerving or hard braking, and other users. These recordings can be interactions, such as failures to yield made through stationary cameras or can provide valuable information dashboard-mounted video cameras.

3-16 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Increasingly, researchers are using programs to automatically identify Evaluation of Children Involved potential events. This eliminates the in Off-Roadway Crashes Using need to scan visually through the Trauma Center Records entire video. Many off-roadway crashes are not reported by law enforcement and Observing interactions between are thus missed when conducting road users can provide valuable safety evaluations using police crash information on the safety effect reports. One group that is particularly of certain road elements, such affected by this lack of data is young as signals or signs, and help children injured by passenger vehicles in driveways and parking lots. This identify the probability of crashes lack of information provides safety under different conditions. If a professionals with little knowledge reliable relationship between the about crash risk factors and actual observations and crashes is known, incident rates that could be used such studies may also provide to allocate resources and promote insights into the potential for safety safety interventions and good design and behaviors. A 2010 study (Rice et issues between road users, such al.) in California used records from as between vehicle drivers and eight trauma centers to identify the pedestrians. frequency and characteristics of these crashes. This study highlighted the However, one of the biggest inconsistencies with external cause- challenges for using observations of of-injury codes used by emergency road user interactions is that they departments, but suggests that there are surrogate measures of safety. is value to surveillance of off-roadway pedestrian injuries at trauma centers as To date, we lack good research a way of identifying incidents that are that would quantitatively equate not captured by other data sources. surrogate measures of safety to crash data. If such relationships Reference: Rice TM, Trent RB, Bernacki K, Rice JK, Lovette B, Hoover E, Fennell were known, safety professionals J, Aistrich, AZ, Wiltsek D, Corman E, could conduct evaluations with a Anderson CL, Sherck J. (2012). Trauma large number of surrogate measures center-based surveillance of nontraffic in a relatively short period of time. pedestrian injury among California This contrasts with the need to wait children. Western Journal of Emergency for years for sufficient crash data to Medicine; 13.2. support a good analysis. Injury Surveillance and Emergency a traffic crash is only one type of Medical Systems Data injury in these medical systems, Injury surveillance systems traffic crash injuries can be a useful (ISS) typically provide data on source of data in bridging the gap emergency medical systems (EMS), between traditional traffic safety hospital emergency departments, and public health issues. Hospital hospital admissions/discharges, records are also often the only trauma registry, and long-term source of information on bicycle rehabilitation. This information and pedestrian crashes that are not is used to track injury causes, recorded by the police, such as those severity, costs, and outcomes. that occur in non-roadway locations Although an injury associated with like parking lots and driveways.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-17 Hospitals often use the external demographics. It can also be used cause of injury classifications to to identify the full magnitude of code causes of patient injuries, crashes for a specific user group or including those from traffic crashes. demographic that is not recorded These data can provide a description or reported by law enforcement. of injury severity, type of crash (e.g., For example, hospital data can motor vehicle passenger, bicyclist), help safety professionals better and, in some cases, the location of understand the number of bicyclist incident. However, the data is often crashes, since many bicycle-related incomplete or non-specific. In order crashes are not reported to law to provide a more comprehensive enforcement. understanding of motor vehicle Hospital data are often difficult crash outcomes, NHTSA developed to use for those who administer the Crash Outcome Data Evaluation roads, primarily the State DOT. The System (CODES), which links crash, data is time consuming to acquire vehicle, and behavior characteristics and may not contain complete to their specific medical and data. Additionally, since there are financial outcomes. Hospital injury no personal identifiers relating data most often includes date, injury hospital injury data to specific crash severity, cause, and demographic records, the linkage is difficult and information. Personal identifying is seldom done. For these reasons, information is not included. State DOTs rarely use these data; it Hospital data can be used by is most often employed by public a variety of governmental and health researchers. However, there non-governmental agencies to continues to be efforts at both investigate the causes of injuries. Federal and State levels to develop Based on this analysis, the agencies better ways to integrate injury can develop a safety campaign surveillance and emergency medical to reduce injuries to particular systems data with crash data.

Hospital data can be used to investigate causes of injuries, and is often the only source of information on some bicycle and pedestrian crashes.

3-18 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Driver History Data information about registered vehicles in a State and is also Departments of Motor Vehicles typically maintained by the DMV. (DMVs) maintain driver history data Vehicle registration systems may on all licensed drivers in the State. also contain information regarding DMVs typically create a driver record commercial vehicles and carriers when a person enters the State registered in a particular State and licensing system to obtain a driver’s licensed to travel in other States. license or when an unlicensed These data can provide information driver commits a violation or is on the vehicle population within a involved in a crash. State driver State or county to be used in large history databases interact with the scale safety analysis. These data National Driver Register (NDR) can also help identify owners in the and the Commercial Driver License event of a crash or traffic violation. Information Systems (CDLIS) to prevent drivers with a history of at- Typical vehicle registration data may fault crashes or inordinate number include owner information, license of citations from obtaining multiple plate number, vehicle make, model, or subsequent licenses. and year of manufacture, body type, vehicle identification number, and The driver history data contain miles traveled. Common data for information such as: commercial vehicles may include JJ Basic identifiers (e.g., name, U.S. Department of Transportation address, driver license number) (DOT) number, carrier information, and inspection or out-of-service JJ Demographics (e.g., age, information. birth date, gender) Citations and Enforcement JJ Information relevant to license and driver improvement actions Citation data refers to data on (e.g., license issue, expiration individual drivers that records any and renewal dates, license illegal actions that were cited by a class, violation dates, law enforcement officer. It includes suspension periods) traffic violations, such as reckless driving, driving under the influence, One challenge with using these data and not carrying adequate car is that they are almost never shared insurance; traffic crashes; driver’s outside a DMV. State or local DOTs license suspensions, revocations, do not have access to these data and cancellations; and failures to while developing their HSIPs (or appear in court. The data can also conducting location specific safety include the traffic infractions that studies). Sharing driver history data have been adjudicated by the courts. nationally is limited and could be improved by creating inter-agency These data are helpful in identifying data sharing partnerships that and tracking those individuals address privacy concerns and allow with a higher potential for unsafe State DOTs to work with the data. driving behaviors. In an attempt to Vehicle Registration Data control crash occurrences, States may monitor high-risk drivers Vehicle registration data includes by reviewing their driver history

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-19 records, paying particular attention actual driving trips through to driver citations. Ideally, States technology placed in the vehicle. track a citation from the time it is This technology typically includes issued by a law enforcement officer video camera views of the driver, through its disposition in a court of speed and vehicle motion sensors, law. Citation information tracked and location tracking equipment. and linked to driver history files Data such as video might be enable States to screen drivers with collected on a continuous basis, or a history of frequent citations for only after certain events like hard actions known to increase crash braking. Using data collected by risk. States have found citation this equipment, researchers are tracking systems useful in detecting able to gather information on the repeat traffic offenders prior to underlying causes of crashes by conviction. It can also be used to observing drivers in a natural driving track the behavior of particular law situation. Frequently collected enforcement agencies and the courts data include road environment with respect to dismissals and plea information, such as weather; bargains. Many law enforcement driver information, such as eye agencies use citations as a method movements; and information of tracking and measuring the on vehicle movement including effectiveness of enforcement efforts. location on the road, acceleration, deceleration, and speed. Some constraints exist with the use of citation and enforcement Strategic Highway data to help prevent crashes. Some Research Program 2 States have difficulty in maintaining The largest naturalistic study in the accurate citation information United States to date is the second because local jurisdictions may Strategic Highway Research Program collect different data elements (SHRP2), which included over 3,400 from varying citation forms. drivers participating in the study. Obtaining and managing judicial SHRP2 data includes over 5,400,000 individual trips and over 36,000 crash, information is also a challenge near crash, and baseline driving events. because of the various levels of court FHWA provides more information on administration and jurisdiction. SHRP2 at https://www.fhwa.dot.gov/ Unfortunately, in some States goshrp2. judges do not have access to the offender’s driver history at the time These data are used to evaluate how of sentencing, so many offenders drivers interact with and react to escape the stricter penalties the road, other road users, and other sanctioned for repeat offenses. environmental features. Driver In addition, the traffic safety observation is used to understand community often lacks access to fundamental issues of driver adjudication information due to behavior and to develop improved privacy concerns. safety countermeasures. The data Naturalistic Driving Data are primarily used in research studies on a variety of topics. The Naturalistic driving data are driver data from the SHRP2 program behavior data collected during have been used to study safety

3-20 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Driving simulators like this one are often used to evaluate driver behavior under specific conditions and in a cost-effective way. issues including prevention of road insightful look at fundamental departures, driver reaction to posted issues of road safety. speed limits, and driver response Driving Simulator Data to curves in the road, in addition to many non-safety-related topics. Due to the high cost of naturalistic driving studies and the rarity of A challenge with collecting a large traffic crashes, driving simulators amount of naturalistic data is the are often used to efficiently and high cost of recruiting participants, safely evaluate driver behavior instrumenting vehicles, and under different conditions. reducing and analyzing the data. Researchers are able to study The process of coding (observing) many different conditions and the behaviors of the driver while complex environments without driving is time-consuming and is exposing drivers to danger typically conducted on a frame-by- through replicating a wide range frame basis, leading to expensive of road, traffic, and environmental data collection and lengthy study conditions, as well as driver periods. The data are highly private behaviors such as distractions, (i.e., contains videos of driver faces), impairment, and fatigue. New types and therefore are typically difficult of road designs can be guided by to access or distribute. Despite these the use of simulators, particularly challenges, naturalistic driving data complex features, such as urban provides a unique and extremely highway interchanges.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-21 Simulators can also be used 2014 643 for driver education to teach 2015 607 people about the effects of driver distractions or to prepare young drivers for different conditions before they encounter them on the road. Truck simulators are used to 309 replicate the driving environment 287 for different types of commercial trucks and used to safely train new drivers. 106

48 Public Opinion Data DOT-Comliant Noncomliant No Feedback from the general Helmets Helmets Helmet public can be a useful source of information for safety professionals. FIGURE 3-4: Observations of Safety professionals can use motorcyclists showed how many were information on road safety issues wearing DOT-compliant helmets (Source: National Occupant Protection Use Survey) and concerns from the public to identify specific locations or types of based on those who self-select conditions where people have real or to provide the information to the perceived traffic safety concerns. researching agencies. Findings There are many different ways to will be subjective as each person collect this information, such as a perceives a condition based on phone-based survey, web-based their individual experiences only. tools (pins on maps or online Different persons perceive different forms), meetings, or intercept issues and recommend different surveys. Common data collected “best” solutions for the same are the type of concern, location, condition. Conclusions based on and type of mode (i.e., walking, survey findings should be used with bicycling, transit user, or driving). care.

These data are typically collected at Behavioral Observation the local level, frequently as part of Observational surveys of road user a transportation planning process behaviors are an effective method or as a collaborative effort with law of data collection on information enforcement. Bringing residents that may otherwise be inaccurately and police officers to join the road recorded due to self-reporting bias safety audit teams or diagnosis or are difficult to capture through teams during their field visits is also other means. Several examples a beneficial way to learn about the of data typically recorded using experiences of the road users in the direct observation are the use of study area. mobile devices (texting or calling), These data may provide valuable right turn on red, safety belt use, insights about what the travelling motorcycle or bicycle helmet use, public perceives as dangerous; and traffic control violations, such however, it may be a biased sample as rolling through stop signs.

3-22 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS These data are collected through Data Users observing road users on the road. While many agencies use safety Large scale surveys collecting a high data, most of them have different number of observations will provide goals. For example, a city traffic the most accurate sample of the road engineer may have a specific scope user population in the study area. for identifying and treating specific Additionally, robust observation data high priority sites, whereas a safety will cover differing road types and analysist with a State may be focused land use characteristics and contain on safety at the system level. observations at different times of Moreover, safety researchers and day, week, and season. An example graduate students may be focused on of a large-scale data collection a whole range of safety evaluations effort is the National Occupant that are not intended to be action Protection Use Survey conducted plans to improve safety at a specific annually by NHTSA. In 2013, over site or system. Each type of data user may have different levels of access to 52,000 occupants were observed in these various types of safety data. nearly 40,000 vehicles. The data, summaries, and evaluations from The following tables provide this program may be viewed on the common uses and data needs for 4 these different types of data users. NHTSA website . 4

https://crashstats. DATA TYPE USEFULNESS ACCESSIBILITY OFTEN PAIRED nhtsa.dot.gov Road characteristics, Crash Essential High Traffic volumes Crash, Road characteristics Essential High Traffic volumes Crash, Traffic volumes Essential High Road characteristics Naturalistic driving Supplemental Moderate Conflicts/avoidance Road characteristics, Supplemental Low maneuvers Traffic volumes Crash, Traffic volumes, Citations Supplemental Low Road characteristics

Driving simulator Supplemental Low Road characteristics

Crash, ACADEMICS AND RESEARCHERS AND ACADEMICS Behavior observation Supplemental Low Road characteristics Injury surveillance Supplemental Very low Driver history Supplemental Very low Vehicle registration Supplemental Very low Public opinion Supplemental Very low

TABLE 3-3 (above/next page): Data Use by Safety Professionals, Academics and Researchers

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-23 DATA TYPE USEFULNESS ACCESSIBILITY OFTEN PAIRED

Road characteristics, Crash Essential High Traffic volumes Road Crash, Essential High characteristics Traffic volumes

Crash, Traffic volumes Essential High Road characteristics Crash, Public opinion Supplemental High Road characteristics Conflicts/avoidance Road characteristics, Non-essential Low maneuvers Traffic volumes Citations Non-essential Low

SYSTEM LEVEL ANALYSIS LEVEL SYSTEM Behavior

SAFETY PROFESSIONALS PROFESSIONALS SAFETY Non-essential Low observation FOR Injury surveillance Non-essential Very low Driver history Non-essential Very low Vehicle registration Non-essential Very low Naturalistic driving Non-essential Very low Driving simulator Non-essential Very low

DATA TYPE USEFULNESS ACCESSIBILITY OFTEN PAIRED Road characteristics, Crash Essential High Traffic volumes Road Crash, Essential High characteristics Traffic volumes Crash,

Traffic volumes Essential High Road characteristics Crash, Public opinion Supplemental High Road characteristics Conflicts/avoidance Road characteristics, Supplemental Low maneuvers Traffic volumes Crash, Traffic volumes,

SPECIFIC SITES SPECIFIC Citations Supplemental Low Road characteristics

FOR Behavior Crash,

SAFETY PROFESSIONALS PROFESSIONALS SAFETY Supplemental Low observation Road characteristics Injury surveillance Non-essential Very low Driver history Non-essential Very low Vehicle registration Non-essential Very low Naturalistic driving Non-essential Very low Driving simulator Non-essential Very low

3-24 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Other Types of Road Safety Data Additional types of data can also be useful to road safety professionals. These types of data may include:

Insurance data Safety program evaluation data (e.g., carrier, policy number, expiration (e.g., surveys, assessments, inspections) date, claims cost) These data can provide feedback on the These data can provide insights into effectiveness of a new safety program. associations between insurance status and safety. Maintenance data (e.g., guardrail replacement) Demographic data (e.g., population by gender, age, rural/ These data may indicate where unreported urban, residence, and ethnicity) crashes are occurring. These data can be used for normalizing crash data to a state’s general population.

EXERCISES

JJ IDENTIFY possible relationships JJ EXPLORE what type of safety analysis between the safety data presented could be made possible using in this chapter and census data (e.g., communication between vehicles traffic safety vs. population density). (V2V) and also between vehicles and infrastructure (V2I - i.e., roads, JJ CONSIDER if, in the future, vehicles intersections, etc.). store pre-crash data in a “black box” type of event recording device. What JJ DETERMINE how safety professionals types of data would you like it to store can incorporate operational data, such and how would you use this data (i.e., as those from dynamic tolling lanes and what types of analysis would you speed sensors, into a safety analysis recommend conducting)? program.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-25 CHAPTER 9 MEASURING SAFETY Improving Safety Data Quality

Quality Measures Of Data Accuracy

The previous chapters in this unit Accuracy is a measure of how have made the case that data are reliable the data are and whether critical when seeking to improve they correctly represent reality. For road safety. However, simply having example, exact crash location is data is not enough. Good decisions an important detail for accuracy. A require good data. When collecting, crash occurring at the intersection recording, maintaining, and of First Street and Main Street analyzing safety data, road safety should be recorded as occurring at professionals must focus on the that intersection. Accurate data are quality of data. Data-driven analysis crucial during the analysis phase to tools are continually advancing and generate road safety statistics and can help set priorities and select to pinpoint safety problems. Errors appropriate safety strategies, but may occur at any stage of the data the need for quality data to drive collection process. Common data these tools is clear. Professionals accuracy errors include: commonly recognize that data JJ Typographic errors (for data quality can be measured on six entered manually ) criteria – timeliness, accuracy, completeness, uniformity, integration, JJ Inaccurate and vague and accessibility. Each of these descriptions of the crash location criteria are presented in this chapter. JJ Incorrect descriptions or entry Timeliness of road names, road surface, Timeliness is a measure of how level of accident severity, quickly an event is available within vehicle types, etc. a data system. State and local JJ Subjectivity on details that rely agencies can use technologies to on the opinion of the reporting automate crash data collection and officer (e.g., property damage quickly process police crash reports thresholds, excessive speed for analytic use. However, some for conditions) agencies still rely on traditional methods, such as paper form data Technology can and is currently collection and manual data entry; being used to improve accuracy and these data collection methods can reduce errors. Automatic internal result in significant time lags. Many data quality checks are important for States, however, are moving closer this purpose. These types of checks to real-time data collection methods would determine if two data fields by using electronic reporting to contain possibly conflicting data, improve the timeliness of data and if so, bring it to the attention collection and submission. of the data analyst. An example of

3-26 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS Many police officers now use in-car computers to complete and submit electronic crash reports, increasing the timeliness of data availability. (Source: Town of Hanover, NH) conflicting data fields would be a are typically not required to report crash type recorded as “rear end” the crash and often agree to work but the crash report says that one out the financial damages personally car was hit on the “side”. or through their automobile insurance policies. In some States, Completeness even when PDOs are reported, they Completeness is a measure of are not always added into the crash missing information. It may range database. from missing data on the individual In addition to the limitations from crash forms to missing information absent data due to unreported due to unreported crashes. crashes, fluctuations in the Unreported crashes, particularly thresholds (i.e., dollar amounts) can non-injury crashes, present a make it difficult to compare data drawback to crash data analysis. from previous years. Unreported Without knowing about these PDO crashes are one of many crashes, we cannot recognize the measures of “completeness” full magnitude of certain types of that road safety professionals crashes (e.g., pedestrian involved must consider when collecting crashes). Non-injury crashes, or and analyzing data. A lack of property damage only (PDO) crashes, complete data hinders the ability to involve damage less than a specified measure the effectiveness of safety threshold (e.g., $1,000); these countermeasures (e.g., safety belts, thresholds vary from State to State. helmets, and red light cameras) or The parties involved in PDO crashes change in crash severity.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-27 Uniformity Crash Data Improvement Program Uniformity is a measure of how consistent information is coded in The Federal government established the Crash Data Improvement Program the data system or how well it meets (CDIP) to provide states with a accepted data standards. Numerous means to measure the quality of the law enforcement agencies within information within their crash database. each State, some of which are not It is intended to provide the states with the primary users of the crash metrics that can be used to establish data, are responsible for crash data measures of where their crash data stand in terms of its timeliness, the collection. The challenge for States accuracy and completeness of the is ensuring there is consistency data, the consistency of all reporting among the various agencies when agencies reporting the information in collecting and reporting crash data. the same way, the ability to integrate One example of inconsistent or non- crash data with other safety databases, uniform data can be the location of and how the state makes the crash data accessible to users. Additionally, CDIP a crash. If one agency, for example was established to help familiarize the the State highway patrol, uses collectors, processors, maintainers, and GPS to document a crash at one of users with the concepts of data quality several entrances (driveways) to a and how quality data help to improve shopping center, but the city police safety decisions. CDIP also included a use a linear reference system (e.g., guide that presents information on each data quality characteristic and how to distance from an intersection), there measure them. is a potential for inconsistent crash location data. Reference: Crash Data Improvement Program, National Highway Traffic Safety The Model Minimum Uniform Administration, https://safety.fhwa.dot. Crash Criteria (MMUCC) is used by gov/cdip/summary.cfm States to ensure uniform crash data. MMUCC is an optional guideline be linked together to merge the that presents a model minimum information in each database into set of uniform variables or data a combined database. Each State elements for describing a motor maintains its own crash database. vehicle crash. This uniformity However, crash data alone do not assists transportation safety typically provide sufficient details professionals and governments in on issues like environmental risk making decisions that lead to safety factors, driver experience, or medical improvements. Similarly, MIRE consequences. Linking crash data provides a recommended list of to other databases, such as road elements to use when reporting road characteristics, driver licensing, and traffic characteristics, thereby vehicle registration, and hospital increasing uniformity of road outcome data assists analysts network data. More information on and planners in evaluating the MMUCC and MIRE is presented at relationship of the circumstances the end of this chapter. of the crash and other factors (e.g., Integration human, road, medical treatment) at the time of the crash. In addition, Data integration is a measure of integrated databases promote whether different databases can collaboration among agencies, which

3-28 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS can lead to improvements in the problem solving. Thus, programs to data and the data collection process. improve data should be in the work programs of all agencies invested in Some data are more challenging to road safety. Data could be improved integrate with other data sets. For by changes in policy, technology, example, hospital data are difficult assessments, and training. to integrate with crash data due to the lack of a common identification Policy system (as well as medical privacy With so many agencies and laws). This is different from crash, organizations involved in the road characteristics, and volume data collection process, published data, which can share a common policy is a necessity. A standard referencing system on the road and set of procedures can provide a thus be integrated and linked more clear expectation of each agency’s easily for analysis. roles and responsibilities in data Spatially-located data in a GIS collection. Federal guidance and system can be integrated simply State legislation or administrative based on spatial position. This policy and regulations generally geographic integration can assist form a basis for policy. An agencies in bringing together data example of Federal guidance that were gathered by various comes from the provision in the departments or agencies that may MAP-21 transportation legislation use different data storage standards that requires States to collect a and reference systems. comprehensive set of roadway and traffic fundamental data elements Accessibility (FDEs) on all public roads5. Accessibility is a measure of how Technology 5 easy it is to retrieve and manipulate safety data in a system, in particular Technology plays an important role Moving Ahead for Progress in the 21st by those entities that are not the in data collection improvement. Century Act, Section data system owners. Complete, Federal legislation provides funds 1112, §148(f)(2) accurate, and timely data easily that allow States to improve their made available to localities, MPOs, data collection systems with and other safety partners can greatly the latest technology for quality enhance transportation planning data collection and integration. and safety investments. Agencies Technology is not static and is or departments who house safety always changing. Some technology data, especially crash data, should examples that help facilitate data consider how accessible the data collection include electronic crash are to external parties and how the reporting systems, GPS location process of obtaining data could be devices, barcode or magnetic streamlined. strip technologies, wireless communications, error checking, Data Improvement Strategies and conflicting fields.

Local, State, and Federal agencies, Assessments as well as non-governmental organizations, require accurate Assessments are official evaluations data to be available for analysis and that government agencies conduct

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-29 to determine the effectiveness of a used in policy development and traffic safety process or program. A investment decisions, infrastructure team of outside experts conducts a improvements, and safety planning. comprehensive assessment of the Through proper education and highway safety program using an training programs, law enforcement organized, objective approach and can have a broader perspective well-defined procedures that: of their contribution to reducing crashes through improved JJ Provide an overview of the data reporting. Other examples program’s current status include training transportation in comparison to professionals on the latest data pre-established standards collection tools and technology, JJ Note the program’s strengths advising court officials and and weaknesses adjudicators on important changes to safety legislation and penalties, JJ Provide recommendations for and training personnel on how to improvement handle crash reports with inaccurate Both FHWA and NHTSA provide or missing information. these types of assessments, such Federal Guidance as the Roadway Data Improvement Program (RDIP), which can improve The following two sections present the quality of an agency’s data examples of Federal guidance that through expert technical assistance leads State agencies into improving and fresh perspectives. When the quality of their safety data. State agencies request an RDIP assessment, an FHWA team reviews Model Minimum Uniform Crash and assesses a State’s roadway Criteria data system for the content of the Statewide motor vehicle traffic data collected; for the ability to crash data systems provide the use, manage and share the data; basic information necessary for and to offer recommendations for effective road safety efforts at any improving the road data. The RDIP level of government—local, State, also examines the State’s ability to or Federal. Unfortunately, the use of coordinate and exchange road data State crash data is often hindered by with local agencies, such as those in the lack of uniformity between and 6 cities, counties, and MPOs . within States. Data definitions, the 6 Training number and type of data elements, and the threshold for collecting Federal Highway Education and training of Administration data varies from jurisdiction to Roadway Safety transportation professionals play jurisdiction. The Model Minimum Data Program, a vital role in improving data Uniform Crash Criteria (MMUCC) http://safety.fhwa. dot.gov/rsdp/ and data collection. For example, was developed to help bring greater technical.aspx law enforcement officers create uniformity to crash data collection the crash data that is used by and provide national guidance to safety professionals to conduct data collectors. MMUCC represents studies and evaluate road safety. a voluntary and collaborative effort Thus, law enforcement need to to generate uniform, accurate, understand how crash data are reliable, and credible crash data to

3-30 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS support data-driven highway safety decisions at a State and a national MMUCC Example Element level. MMUCC serves as a foundation The following is the MMUCC format for for State crash data systems. “Person Data Element Derived from Collected Data.” Since MMUCC is a minimum set of recommended crash data, States PD1. Age and localities may choose to collect Definition: The age in years of the person additional motor vehicle crash- involved in the crash related data elements if they feel Source: This data element is derived from the data are necessary to enhance Date of Birth (P2) and Crash Date and decision-making. Implementation Time (C3). of MMUCC is a collaborative effort involving the Governors Highway Attribute: Safety Association, FHWA, NHTSA, • Age in years and the Federal Motor Carrier Safety Rationale: Age is necessary to Administration (FMCSA). determine the effectiveness of safety The MMUCC Guideline is updated countermeasures appropriate for various age groups. every four or five years to address emerging highway safety issues, simplify the list of recommended elements, refer to the latest edition data elements, and clarify of the MMUCC Guideline located at definitions of each data element. www.mmucc.us.

MMUCC Data Elements The MMUCC data elements represent a core set of data elements. The MMUCC consists of data elements fourth edition (2012) of the MMUCC recommended to be collected by Guideline contains 110 data elements investigators at the crash scene. and recommends that States collect From the crash scene information, all 110 data elements. To reduce the additional data elements can be data collection burden, MMUCC derived to assist law enforcement. recommends that law enforcement Additional data elements are at the scene should collect 77 of the available through linkage to driver 110 data elements. From crash scene history, hospital and other health/ information, 10 data elements can injury data, and road inventory data. be derived, while the remaining 23 Each group of data elements has a data elements should be obtained unique identifier that describes the after linkage to other State data type of data element and whether it files. States unable to link to other is derived or linked data. State data to obtain the MMUCC MMUCC data elements are divided linked data elements should collect, into four major groups that describe at a minimum, those linked data various aspects of a crash: crash, elements feasible for collecting on vehicle, person, and roadway. Each the crash report. At the same time, data element includes a definition, States should work to develop data a set of specific attributes, and a linkage capabilities so they eventually rationale for the specific attribute. are able to obtain, via linkage, all of the information to be generated by For the entire list of MMUCC data the MMUCC linked data elements.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-31 ROADWAY SEGMENT ROADWAY ALIGNMENT

Segment location/linkage elements Horizontal curve data Segment classification Vertical curve data Segment cross section Segment roadside descriptors Other segment descriptors ROADWAY JUNCTION Segment traffic flow data Segment traffic operations/control data At-grade intersection/junctions Other supplemental segment descriptors Interchange and ramp descriptors

FIGURE 3-5: MIRE Data Elements Category Descriptors (Source: MIRE version 1.0)

Model Inventory of Roadway Elements JJ Roadway junction descriptors

Critical safety data include not Most State and local transportation only crash data, but also road agencies do not have all the data inventory data, traffic data, and needed to use analysis tools such other information. State DOTs need as SafetyAnalyst, the Interactive accurate and detailed data on road Highway Safety Design Model, and characteristics as they develop other tools and procedures identified and implement strategic highway in the Highway Safety Manual. safety plan (SHSPs) and look toward MIRE provides a structure for road making more data driven safety inventory data that allows State and investments. local transportation agencies to use these analysis tools with their own With the need for and availability of data rather than relying on default so many types of data, the question values that may not reflect local becomes “How can transportation conditions. agencies be sure that they are collecting the necessary roadway As the need for road inventory data to make effective road safety information has increased, new and decisions?” MIRE is a vitally more efficient technologies to collect important resource that defines the road characteristics have emerged. data needed to help transportation However, the collected data need a agencies build a road characteristics framework for common information database that will lead to good sharing. Just as MMUCC provides safety analysis. MIRE defines 202 guidance for consistent crash data individual characteristics of the road elements, MIRE provides a structure system that should be collected. for roadway inventory data elements These characteristics are referred to using consistent definitions and as data elements. The elements fall attributes. It defines each element, into three broad categories: provides a list of attributes for coding, and assigns a priority status JJ Roadway segment descriptors rating of “critical” or “value added” JJ Roadway alignment descriptors based on the element’s importance for use in analytic tools, such as

3-32 UNIT 3: MEASURING SAFETY ROAD SAFETY FUNDAMENTALS SafetyAnalyst. to integrate different types of safety data. If all safety data are The latest version of MIRE can be referenced to the same system, the viewed and downloaded from the road characteristics data can be FHWA Office of Safety site, http:// linked with the crash data, which safety.fhwa.dot.gov/tools/data_tools/ would permit the State to identify mirereport/. locations on all public roads where Figure 3-5 displays a breakdown of crash patterns are occurring that the major data element categories can be reduced through known and subcategories contained in countermeasures. MIRE. MIRE further breaks down In most States, development of a each subcategory into individual common referencing system for all 7 data elements. For a complete listing public roads will require significant Memorandum on of MIRE data elements, refer to the effort and cooperation with local Geospatial Network MIRE publication. for All Public Roads, agencies. The Federal Highway Office of Highway While the complete list of MIRE Performance Monitoring System Policy Information, requires GIS-based referencing for August 7, 2012. elements is rather extensive, there Accessed October are a basic set of elements within all roads in the Federal-aid highway 2017 at https:// MIRE called the Fundamental Data system, interstate highways, and www.fhwa.dot.gov/ policyinformation/ Elements (FDE) that an agency public roads not classified as local hpms/arnold.pdf needs to conduct safety analyses roads or rural minor collectors.7 regardless of the specific analysis However, significant travel occurs tools used or methods applied. As on local roads and rural minor discussed, the need for improved collectors. Some local agencies and more robust safety data is have or are developing, their own increasing due to the development GIS-based referencing systems for of a new generation of safety data roads in their inventory data. Light analysis tools and methods. detection and ranging (LIDAR) systems are often used to accurately Linking Data Through A survey the road network. The State Referencing System should work with local agencies to incorporate these referencing The types of road safety data systems into the State base map. presented in this unit are only useful Once the referencing systems as much as they are capable of being are combined, attribute data for linked through a common geospatial additional mileage can be added relational location referencing when either State or local agencies system. States recognize that they develop or expand inventories. must have a common relational Moreover, as stated above, this will location referencing system (i.e., lead to the ability to link crashes geographic information system or with inventory and traffic data, linear referencing system) for all enabling the State to use the more public roads if they are going advanced problem identification methods on more and more miles of public roads.

ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-33 Conclusion as conflict observations, emergency medical data, and citation data, can Data are crucial to improving road be useful in a supplemental role for safety. Safety data consist of various specific studies. Regardless of the kinds of data that can be used type of safety data, the quality of the to identify safety problems and data is vitally important. Agencies priorities so that safety partners that collect safety data should in many agencies can address strive to improve their timeliness, important issues. Data such as crash accuracy, completeness, uniformity, data, traffic volume data, and road integration, and accessibility to characteristics data are often used maximize their potential to drive and are critical for safety analysis good decisions. by many agencies. Other data, such

EXERCISES

JJ SELECT a scenario below. Assume that JJ You are recommending safety you are using crash data as your primary improvements to an interchange data to inform your decisions. Explain that was identified based on having how each of the six quality criteria a higher number of expected discussed in this chapter could affect crashes than other interchanges of your evaluation of the current safety the same type. situation and your recommendations. Given the scenario you selected above, JJ You are prioritizing intersections in how do you think the availability of a city to be treated with enhanced other types of data could affect your visibility treatments, such as recommendations? Such data may larger signs, wider markings, and include any of the data types covered additional signal heads. in Chapter 3.2. (e.g., EMS and hospital injury data, enforcement citations, JJ You are developing a public public complaints, or other data). What outreach effort to communicate additional information could this reveal? the need to yield to pedestrians at crosswalks. You wish to focus your JJ IDENTIFY programs or policies that exist efforts to the areas of the city where in your state or local agency to improve failing to yield to pedestrians is the data. This may include any of the types most rampant. of safety data covered in Chapter 3.2.

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ROAD SAFETY FUNDAMENTALS UNIT 3: MEASURING SAFETY 3-35 UNIT 4 Solving Safety Problems

LEARNING OBJECTIVES

After reading the chapters and completing JJ DEFINE the process of conducting exercises in Unit 4, the reader will be able to: site-level and system-level safety management JJ IDENTIFY three major components of road safety management JJ USE safety data to identify safety issues and develop strategies to solving those issues

4-b UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS CHAPTER 10 UNIT 4: SOLVING SAFETY PROBLEMS Road Safety Management

Road safety management refers to the process of identifying safety problems, devising potential strategies to combat those safety problems, and selecting and implementing the strategies. Effective safety management is also proactive and looks for ways to prevent safety problems before they arise. High quality safety data should be used to determine the nature of the road safety problems and how best to solve them. As discussed in Unit 3, the clearest and most readily available indicators of road safety problems are crash data. These data can be used to identify safety problems on a large or a small scale. Other data, such as roadway characteristics, traffic volume, citations, and driver history, can be integrated with crash data to assist while the agency strives to improve in identifying safety trends and high its data, the data on hand should be priority locations. used in the process of identifying Data quality issues should not safety problems and devising prevent a data-driven process solutions to those problems.

Every transportation agency will Data needs for safety analysis acknowledge that it does not have High quality safety analysis perfect data. All data have issues demands high quality data. related to accuracy, coverage, Unfortunately, poor data availability timeliness, and other factors. One 1 and low quality limit the types of agency’s crash data may have an incomplete record of low severity analyses that can be conducted. Applying Safety Data and Analysis to crashes. Another agency may The data requirements depend on Performance-Based have very little data on the traffic the type of analysis and what safety Transportation questions are being asked. Table Planning, volume on low volume rural roads. e-Guidebook, However, data quality issues should 4-1 provides examples of various FHWA, http://safety. categories of safety analysis and lists fhwa.dot.gov/tsp/ not prevent a transportation agency fhwasa15089/ from using the data to drive its the data that would be needed to appb.cfm safety management efforts. Even conduct them.1

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-1 SAFETY ANALYSIS QUESTION DATA NEEDS

How many fatalities Total crashes and serious injuries are

occurring in my area? Total fatalities and serious injuries — roadway ownership, How does this High-level roadway data functional classification compare to other areas of my State? Agency geographic boundary information B ENCHM A RKING

What type of road users Crash severity — fatality, injury type, are involved in crashes? property damage only CTORS When are the Crash incidence data — time of day, day, crashes occurring? month, weather, etc.

What are the major Crash type — road departure, intersection, contributing factors head-on, angle, etc. to crashes? Contributing factors — age, impairment, ND A ND TRENDS A SH seatbelt usage, speed, etc. CR A F B UTING CONTRI

What locations Crash severity (intersections or

segments) show the Crash location most potential for Roadway and roadside characteristics — intersection safety improvements? control, number of lanes, presence and type of shoulder, presence and type of median, posted speed, horizontal and vertical alignment, etc.

Traffic volume data — intersection total entering traffic volume, roadway segment volume per million vehicle miles.

Calibrated safety performance functions, if predictive methods are used FETY IMPROVEMENT S A FETY FOR SITES

What are the common Crash severity characteristics of

locations with crashes? Crash location — intersection What are the Roadway and roadside characteristics

CTORS control, number of lanes, presence and type of countermeasures shoulder, presence and type of median, posted to address these speed, horizontal and vertical alignment, etc. characteristics? — intersection total entering How should we prioritize Traffic volume data traffic volume, roadway segment volume per system-wide million vehicle miles. implementation? FETY RISK F A RISK S A FETY

TABLE 4-1: Safety analysis categories, questions, tools and data needs.

4-2 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Safety data as by the National Highway Traffic Performance performance measures Safety Administration (NHTSA) and the Governors Highway Safety measure A transportation agency has many Association (GHSA) that could be A numerical types of data at its disposal for used to identify safety priorities.2 metric used identifying safety problems, but the The sources of the data could be to monitor changes agency must select which type(s) State crash data files, the Fatality in system Analysis Reporting System (FARS), of data will be the performance condition and measures used to identify the road surveys conducted by the State, performance safety emphasis areas. Federal or grant applications from law against legislation has focused increasingly enforcement and other departments. established visions, goals, on fatal crashes and serious injury The section on Network Screening and objectives. crashes as performance measures in Chapter 11 presents a more for road safety. detailed discussion of crash-based performance measures and how they Table 4-2 provides examples of can be used to identify sites that are 2

performance measures developed high priority for safety treatment. National Highway Traffic Safety Administration DESCRIPTION SOURCES (NHTSA). 2007. Performance Number of traffic fatalities (three-year or five-year moving averages) FARS Measures Discussion. 408 Team Document State crash Number of serious injuries in traffic crashes #005, October data files 29, 2007. National Highway Fatalities/VMT (including rural, urban, and total fatalities) FARS, FHWA Traffic Safety Administration. Number of unrestrained passenger vehicle occupant fatalities, seat positions FARS

Number of fatalities in crashes involving a driver or motorcycle operator FARS with a blood alcohol concentration of .08 g/dL or higher

Number of speeding-related fatalities FARS

Number of motorcyclist fatalities FARS

Number of unhelmeted motorcyclist fatalities FARS

Number of drivers 20 or younger involved in fatal crashes FARS

Number of pedestrian fatalities FARS

Observed seat belt use for passenger vehicles, front seat outboard occupants Survey

Number of seat belt citations issued during grant-funded Grant activity enforcement activities reporting

Number of impaired-driving arrests made during grant-funded Grant activity enforcement activities reporting

Grant activity Number of speed citations issued during grant-funded activities reporting

TABLE 4-2: Safety performance measures and data sources (Source: NHTSA 2007)

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-3 Components of Levels of safety management

safety management Although all road safety The safety management process management follows the same can be viewed in three general three general components listed components. These components above, the specific steps of the are carried out by the agency (or safety management process will be agencies) responsible for managing different depending on the scope. the safety of the road system: The process might be intended to JJ Identifying safety problems – The address specific site-level issues, agency uses crash data and other such as crash patterns at high safety data to identify road safety priority intersections, curves, or problems or problem locations. corridors. On a larger scale, the JJ Developing potential safety process might be intended to strategies – The agency develops address system-level issues, such as potential strategies to address problems that can be addressed by the identified safety problems. policies, design standards, or broad These strategies might also be ranging campaigns of education or referred to as countermeasures enforcement. The following chapters or treatments. will discuss safety management for JJ Selecting and implementing these two levels: Chapter 11 presents strategies – The agency weighs site-level safety management; the potential strategies and Chapter 12 presents system-level decides which ones to implement. safety management.

4-4 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS CHAPTER 11 UNIT 4: SOLVING SAFETY PROBLEMS Site-Level Safety Management

Site-level safety management 1 NETWORK SCREENING is the process of identifying and addressing safety issues at high priority sites. This contrasts with 2 DIAGNOSIS safety issues that are addressed for Site an entire transportation system (i.e., A narrowly all roads in a city, county, or State). 3 COUNTERMEASURE defined System-level safety management is SELECTION location of interest for covered in Chapter 12. safety analysis, 4 ECONOMIC APPRAISAL such as an Agencies responsible for road intersection, safety often conduct some form road section, of site-level safety management. interchange, They identify particular sites of 5 PROJECT PRIORITIATION or midblock crossing. concern and determine how best to address the safety problems at 6 SAFETY EFFECTIVENESS these priority sites. The methods EVALUATION of identifying priority sites and the safety strategies used to treat the sites differ according to the FIGURE 4-1: Schematic Illustrating the type of agency. A department of Steps of Site-level Safety Management transportation (DOT) may install a sign or pavement marking; a law enforcement agency might increase When discussing site-level enforcement in the area of the site. safety management, these three Regardless of the type of agency, it components can be further divided is important to conduct site-level into six distinct steps. This six- safety management in a manner that step process is common to the uses good analysis methods driven engineering discipline and is presented in Part B of the first by safety data. edition of the Highway Safety 3 Chapter 10 presented road safety Manual3 (HSM). The process, shown management in terms of three in Figure 4-1, will be the framework Highway Safety Manual, First general components: for the discussion of site-level safety edition, American management in this chapter. The Association of J J Identifying safety problems material presented in this chapter is State Highway Transportation JJ Developing potential based on the guidance presented in Officials, 2010. safety strategies the HSM and material from a series of documents entitled “Reliability JJ Selecting and of Safety Management Methods” implementing strategies published by FHWA. These FHWA

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-5 SAFETY MANAGEMENT COMPONENTS STEPS OF SITE-LEVEL SAFETY MANAGEMENT 4 IDENTIFY Step 1. Network screening: Identify locations that could benefit SAFETY from treatments to reduce crash frequency and severity. Srinivasan, R., F. Gross, PROBLEMS B. Lan, G. Bahar (2016), Reliability of Safety Management Step 2. Diagnosis: Identify crash trends and patterns based on Methods: Network reported crashes, assess the crash types and severity levels, Screening, Report No. FHWA-SA-16-037, and study other elements that characterize the crashes. Federal Highway Administration, DEVELOP Step 3. Countermeasure selection: Identify appropriate Washington, D.C. POTENTIAL countermeasures to target crash contributing factors and SAFETY SOLUTIONS reduce crash frequency and severity at identified locations. 5

Srinivasan, R., G. Step 4. Economic appraisal: Estimate the economic benefit and Bahar, F. Gross (2016), cost associated with implementing a particular countermeasure Reliability of Safety or set of countermeasures. Management Methods: Diagnosis, Report No. FHWA-SA-16-038, SELECT AND Step 5. Project prioritization: Develop a prioritized list of Federal Highway IMPLEMENT safety improvement projects, considering available resources. Administration, STRATEGIES Washington, D.C. Step 6. Safety effectiveness evaluation: Evaluate how a particular countermeasure (or group of countermeasures) has affected 6 crash frequency and severity where it was installed. Bahar, G. R. Srinivasan, F. Gross, (2016), Reliability of Safety TABLE 4-3: Steps of the Site-level Safety Management Process Management Methods: Countermeasure Selection, Report No. JJ Safety effectiveness evaluation FHWA-SA-16-039, documents provide in-depth Federal Highway guidance and examples on the - The safety effectiveness Administration, following topics: evaluation guide describes Washington, D.C. various methods and the JJ Network screening – The network latest tools to support safety 7 screening guide describes various effectiveness evaluation.7 methods and the latest tools to Srinivasan, R., F. Gross, support network screening.4 JJ Systemic safety programs - The G. Bahar (2016), systemic safety programs guide Reliability of Safety JJ Diagnosis - The diagnosis Management Methods: describes the state-of-the-practice Safety Effectiveness information guide describes and the latest tools to support Evaluation, Report No. various methods and the latest systemic safety analysis.8 FHWA-SA-16-040, 5 Federal Highway tools to support diagnosis. Administration, The six steps of the site-level safety Washington, D.C. JJ Countermeasure selection - management process relate to the The countermeasure selection three general components of safety information guide describes management as shown in Table 4-3. 8 various methods and the Each step is presented in more detail See next page. latest tools to support through the following sections countermeasure selection.6 in this chapter.

4-6 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS intersection that has many crashes, Step 1. Network screening 8 but a closer examination reveals Network screening refers to the that most crashes are low speed, low (from previous page) process of selecting high priority Gross, F., T. Harmon, severity rear-end crashes. The crash sites that need safety treatment, G. Bahar, K. Peach severity method would lower the (2016), Reliability of often through an analysis of crash Safety Management priority of this intersection in favor data. There are many ways in Methods: Systemic of other sites where more serious Safety Programs, which an agency can use crash data crashes occur. Report No. to prioritize sites, ranging from FHWA-SA-16-041, Federal Highway simplistic methods, which are easy Some agencies prioritize sites Administration, to understand and implement but by the historical crash rate. This Washington, D.C. can be inaccurate or ineffective, method incorporates traffic volume to more advanced methods, which to augment the crash data. The require statistical expertise and crash frequency at a site is divided Crash more data but provide a better by the traffic volume – either the frequency prioritization of sites. annual average daily traffic (for road The number For many years, the most prevalent segments), total entering volume of observed methods for ranking specific sites (for vehicle traffic at intersections), crashes for safety improvements were based or other volumes, such as pedestrian per year. on historical crash data alone. Many crossing volume. The typical unit agencies still use these methods for this method is crashes per to allocate their road safety funds. 100 million vehicle miles traveled Crash Agencies that prioritize sites by for road segments or crashes per severity historical crash frequency identify 100 million entering vehicles for those sites that have the highest intersections. Crash rate in these The level of number of crashes in a certain injury severity units is calculated as: of the crash time period (typically three to five as an event, years). This serves to assist agencies Crash rate per (C×100,000,000) typically in addressing the magnitude of 100 million vehicle = determined the problem, that is, attempting miles traveled (V×365×N×L) by the highest to address the highest number of severity injury of any person crashes. By its nature, this method C = Number of crashes in the study period involved in typically identifies sites that have the crash. high amounts of traffic (either V = Traffic volumes using average annual vehicles, pedestrians, or other road daily traffic (AADT) volumes users). However, this method may N = Number of years of data miss abnormally hazardous sites Crash rate that do not present a relatively L = Length of the roadway segment in miles The number large number of crashes. Another of observed variation of the crash frequency crashes method uses crash severity, in This approach of prioritizing sites by per unit of which agencies weight the crash crash rate serves to counteract the traffic volume passing through frequency by giving greater weight bias of crash frequency that overly the location. to higher severity crashes. This prioritizes sites with high volume, method counteracts some of the since higher volume decreases bias in the crash frequency method. the crash rate. However, it may For example, a general high crash inefficiently prioritize sites with frequency may prioritize a busy very low volumes.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-7 Agencies might use a combination of these two methods. They may set Comparing road segments by a minimum crash rate to generate crash frequency and rate an initial list of priority sites and Road Segment A: A three-mile section of then prioritize that group by crash road that has had four crashes over five frequency or severity. Regardless, years and has a traffic volume of4,000 these simplistic methods are known vehicles per day. to have potential biases. One of Road Segment B: A three-mile section the most prevalent biases is that of road that has had 10 crashes over five the crash history used to prioritize years and has a traffic volume of12,000 sites with these methods usually vehicles per day. reflects only the short-term trend If an agency is comparing these of crashes. Given that the year- segments based on crash frequency, to-year occurrence of crashes at they would prioritize road segment B for having 10 crashes compared to road a location is random, it can be segment A which had four crashes. the case that a short-term crash history (one to three years) may If comparing these segments based on be relatively high, but in the long crash rate, the agency would calculate the crash rate of road segment A as run (ten years), the crashes would Regression- (4 crashes x 100,000,000) / (4,000 to-the-mean return to a lower amount, even if vehicles per day x 365 x 5 years x 3 miles) no safety improvements were done. = 18.2 crashes per 100 million vehicle The fact that miles traveled. Following the same a short term This effect creates selection bias or calculation, road segment B has a rate of examination of regression-to-the-mean (RTM) bias in 15.2 crashes per 100 million vehicle miles crash history the safety analysis of this location. traveled. According to crash rate, the at a location is agency would prioritize road segment A. likely inaccurate As the years progressed, many The prioritization of these two segments (e.g., lower or transportation safety professionals changes when traffic volume is taken higher than recognized that while these into account. its true safety simplistic methods did identify performance). sites that benefited from safety When a longer pushed forward a movement to time period of improvement, they were not the identify “sites with promise.”9 The crash history is locations where safety funds could examined, the be spent the most effectively. The main idea was to identify sites that crash frequency selection of high crash sites was experienced more crashes than will “regress” subject to RTM bias. Also, sites would be expected from a site with to its “mean” with high numbers of crashes were that particular set of characteristics. and provide a In many cases, these abnormally better picture typically complex and required performing sites could be addressed of the long term expensive reconstruction in order average crash to reduce crashes appreciably. The with low cost safety treatments, such as larger signs or pavement frequency. question became, “How could road markings with greater visibility. This safety funds be spent in a way that approach uses statistical regression provided the biggest bang for the 9 models that predict crashes for a buck?” given set of characteristics. These Hauer, E. (1997), Observational Before As the science of road safety models demonstrate the advantage After Studies in Road advanced, researchers developed of bringing together different types Safety, Elsevier Science, New York. more advanced approaches of safety data, which in this case for prioritizing sites for safety could include crash data, roadway improvements. Dr. Ezra Hauer characteristics, and traffic volume.

4-8 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS The most basic of these regression of the specific site. This means methods calculates predicted that the predicted crash value is Predicted crashes. This method requires unaffected by the bias caused by crashes information about certain geometric RTM. Using SPFs, transportation The frequency and operational characteristics, such agencies can predict crash values for of crashes per year that would as traffic volume, number of lanes, many sites and prioritize the sites and type of road. be predicted according to the highest predicted for a site based An SPF is developed or calibrated values. Another use of the predictive on the result using data from an entire method is in systemic safety of a crash prediction jurisdiction or State, so it is treatments, presented in Chapter 12 model, called independent of the crash history under Risk Based Prioritization. a safety performance ACCOUNTS ACCOUNTS ACCOUNTS function (SPF). FOR TRAFFIC FOR FOR CRASH PERFORMANCE MEASURE VOLUME RTM BIAS SEVERITY

1. Average crash frequency No No Not explicitly*

2. Crash rate Yes No Not explicitly*

3. Equivalent property damage only No No Yes (EPDO) average crash frequency

4. Relative severity index No No Yes

5. Critical rate Yes No Not explicitly*

6. Excess predicted average crash No No Not explicitly* frequency using method of moments

7. Level of service of safety Yes No Not explicitly*

8. Excess predicted average crash Yes No Not explicitly* frequency using SPFs

9. Probability of specific crash types Not affected No Not explicitly* exceeding threshold proportion by RTM bias**

10. Excess proportion of Not affected No Not explicitly* specific crash types by RTM bias**

11. Expected average crash frequency Yes Yes Not explicitly* with empirical Bayes adjustments

12. EPDO average crash frequency Yes Yes Yes with EB adjustment

13. Excess expected average crash Yes Yes Not explicitly* frequency with EB adjustment

* While these measures do not explicitly ** These two measures will not be affected by mention severity, analysts can adapt any of the RTM only if they are based on data from a measures to consider any severity level. long time period.

TABLE 4-4: Performance Measures for Network Screening (Source: Highway Safety Manual, 1st ed.)

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-9 10 Where can I get safety performance functions for my State?

Srinivasan, R., SPFs can be obtained in two ways: The crashes predicted by the SPF are D. Carter, and compared to the crashes observed on the K.Bauer (2013), 1) SPFs can be developed from scratch Safety Performance State’s roads, and an analyst calculates using crash, roadway, and traffic volume Function Decision a calibration factor to adjust the SPF data from roads and intersections in the Guide: SPF prediction appropriately for the State. Calibration vs SPF State. This requires significant data to be Development, collected on hundreds of sites. A statistical SPF development or calibration is typically Report No. expert must use these data to develop SPFs FHWA-SA-14-004, handled by the State DOT. FHWA provides Federal Highway that are tailor made for that State. guidance on deciding between developing Administration, a new SPF or calibrating an existing one.10 Washington, DC. 2) SPFs can be obtained from national resources, such as the HSM; then States that decide to develop new SPFs calibrated for the particular State of can refer to guidance in a related FHWA publication.11 NCRHP provides guidance 11 interest. This requires data to be collected on a smaller number of sites than is for those who decide to calibrate 12 R. Srinivasan and required for developing a new SPF. existing SPFs. K. Bauer (2013), Safety Performance Development The first edition of the HSM lists site (see more detailed discussion Guide: Developing Jurisdiction-Specific several benefits of the predictive of the EB method later in this step). SPFs, Report method, including: Some agencies may also calculate FHWA-SA-14-005, excess crashes as a measure for site Federal Highway JJ RTM bias is addressed as the Administration, prioritization. This is the difference method concentrates on long- Washington, DC between the expected crashes and the term expected average crash observed crash frequency at the site. frequency rather than short- 12 term observed crash frequency. Performance measures Bahar, G (2014), JJ Reliance on availability of in network screening User’s Guide to Develop Highway limited crash data for any one Safety Manual site is reduced by incorporating The key to effective network screening Safety Performance is selecting an appropriate performance Function Calibration predictive relationships based on Factors, HR 20- data from many similar sites. measure. Network screening 7(332), National methods should appropriately Cooperative JJ The method accounts for the account for three major factors that Highway Research Program, American fundamentally nonlinear can affect the screening outcome: Association of relationship between crash State Highway and frequency and traffic volume. JJ Differences in traffic volumes Transportation Officials, Standing JJ Possible bias due to RTM Committee on Agencies can also use the predicted Traffic Safety, crashes in combination with actual JJ Crash severity Washington, DC. crash history at the site of interest to calculate expected crashes. A method Table 4-4 lists the thirteen called empirical Bayes (EB) brings performance measures discussed in Expected these two values together to reflect the HSM with an indication of their crashes, a crash frequency that incorporates ability to account for these major excess the general crash prediction from the factors. While some measures directly crashes SPF with the real world experience account for crash severity (e.g., See next page. of crash history at the site to provide relative severity index), analysts an accurate estimation of how many can adapt any of the measures to crashes should be expected at the account for crash severity.

4-10 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Accounting for differences such as SPFs, are more appropriate in traffic volumes than linear relationships, such as Expected crash rates to account for differences crashes As discussed earlier, analysts have in traffic volume among sites. The frequency traditionally used crash rates to of crashes SPFs are a more reliable method to account for differences in traffic per year that account for differences in traffic represents the volume among sites. Crash rate volume among sites because they combination of is the ratio of crash frequency to reflect the nonlinear relationship the predicted exposure, which is typically the between crash frequency and traffic crashes and traffic volume. Crash rates implicitly the observed volume. The SPF is an equation that crashes that assume a linear relationship represents a best-fit model that actually between crash frequency and traffic relates annual observed crashes to occurred at volume; however, many studies the site characteristics including the site. have shown that the relationship annual traffic volume and other between crashes and traffic volume site characteristics. Typically, SPFs is nonlinear, and the shape of this are estimated for a particular crash Excess relationship depends on the type type for a type of facility (e.g., crashes of facility. Nonlinear relationships, run-off-road crashes on rural two The difference between the 40 expected crashes and the observed crash 30 frequency at the site.

20

10 Predicted Crash Crash Frequency Predicted

0 Traffic Volume (AADT) 100,000

FIGURE 4-2: Example of SPF for multi-vehicle crashes on rural, 4-lane freeways

10

5 Predicted Crash Crash Frequency Predicted

0 Traffic Volume (AADT) 100,000

FIGURE 4-3: Example of SPF for single-vehicle crashes on rural, 4-lane freeways

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-11 lane roads) using data from an entire jurisdiction or State. Figure SPF Example 1 4-2 and Figure 4-3 show example Some States use Safety Analyst, a SPFs where the points represent software tool from AASHTO, to identify observed crashes at specific traffic sites that may benefit from a safety 14 volumes for individual sites, and treatment. The following is an SPF from Safety Analyst that predicts the solid line represents the best- the total number of crashes on rural fit model (i.e., the SPF). If the multilane divided roads: relationship between exposure and -5.05 0.66 crash frequency were linear, then P = L × e × (AADT) the solid line would be a straight P is the total number of crashes in one line instead of a curve. These two year on a segment of length L. figures also demonstrate the nature This is a relatively simple SPF where the 13 of SPFs – each curve is different. For predicted number of crashes per mile the rural, four lane freeways used in is a function of just AADT. For example, R. Srinivasan and this example, multi-vehicle crashes if the AADT is 45,000, then the predicted K. Bauer (2013), Safety Performance rise exponentially with more traffic number of crashes for a one mile segment Development volume (Figure 4-2) but single- based on the SPF will be the following: Guide: Developing Jurisdiction-Specific vehicle crashes behave differently; P = 1 × e-5.05 × 450000.66 SPFs, Report they level off with increasing levels = crashes per year FHWA-SA-14-005, 7.55 Federal Highway of traffic volume (Figure 4-3). Administration, Washington, DC. An SPF produces the average number of crashes that would be predicted not always be possible due to for sites with a particular set of the availability of data or lack of 14 characteristics. By comparing a statistical expertise. In that case, site’s observed number of crashes http://www. the SPFs developed from another with the predicted number of safetyanalyst.org/ jurisdiction could be calibrated using crashes from an SPF, it may be data from the jurisdiction with the possible to identify sites that study sites.15 15 experience more crashes than one would expect from a site with that Avoiding bias due to G. Bahar and E. particular set of characteristics. Hauer (2014), Users regression-to-the-mean Guide to Develop Sites where the observed number HSM SPF Calibration of crashes is larger than the Factors, NCHRP As previously discussed, RTM Project 20-7(332). predicted number of crashes from describes the situation when an SPF warrant further review and periods with relatively high crash diagnosis. Two measures in Table frequencies are followed by periods 4-4, level of service of safety (LOSS) 16 with relatively low crash frequencies and the excess predicted average Susan Herbel, simply due to the random nature of crash frequency using SPFs, use Lorrie Laing, crashes. Figure 4-4 illustrates RTM, Colleen McGovern the observed crash frequency and comparing the difference between (2010), Highway predicted frequency from an SPF to Safety Improvement short-term average and long-term Program (HSIP) identify sites with promise. 16 Manual, FHWA- average crash history. Due to RTM, SA-09-029, Ideally, SPFs should be estimated the short-term average is not a Federal Highway using data from the same reliable estimate of the long-term Administration, Washington, DC. jurisdiction as the site(s) being crash propensity of a particular studied.13 However, that may site. If an agency selects sites based

4-12 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS SPF Example 2 Bauer and Harwood17 provide a more a crash prediction that is more tailored to complex SPF for fatal and injury crashes on characteristics of the site, such as curve 17 rural two lane roads. This model provides radius and vertical grade of the road: Bauer, K. and NFI = exp [-8.76+1.00×ln(AADT)+0.044×G+0.19×ln(2×5730/R)×IHC Harwood, D., Safety +4.52×(1/R)(1/L )×I ] Effects of Horizontal c HC Curve and Grade N = fatal-and-injury crashes R = curve radius (ft); missing for tangents Combinations on FI Two-Lane Highways, per mile per year Federal Highway IHC = horizontal curve indicator: AADT = annual average daily traffic 1 for horizontal curves; 0 otherwise Administration, Report No. FHWA- (vehicles/day) HRT-13-077, January LC = horizontal curve length (mi); G = absolute value of percent grade; 0% not applicable for tangents 2014. for level tangents; ≥ 1% otherwise ln = natural logarithm function on high short-term average crash One approach to address RTM bias history, crashes at those sites may is to use the EB method. The EB be lower in the following years due method is a statistical method to RTM, even if the agency does not that combines the observed crash install countermeasures at those frequency (obtained from crash sites. reports) with the predicted crash frequency (derived from the If RTM is not properly accounted for, appropriate SPF) to calculate the sites with a randomly high count expected crash frequency for a site of of crashes in the short term could interest. This method pulls the crash be incorrectly identified as having count towards the mean, accounting a high potential for improvement, for the RTM bias. and vice versa. In this case, scarce resources may be inefficiently used The EB method is illustrated in on such sites while sites with a truly Figure 4-5, which illustrates how high potential for cost effective the observed crash frequency is safety improvement remain combined with the predicted crash unidentified. frequency based on the SPF.18 The 18

Short Term Susan Herbel, average Lorrie Laing, Colleen McGovern (2010), Highway Safety Improvement Program (HSIP) Manual, FHWA- Long Term SA-09-029, average Federal Highway Administration, Washington, DC.

Observed Crash Crash Frequency Observed Short Term average Years

FIGURE 4-4: Chart to illustrate RTM phenomenon (Source: HSIP Manual, 2010)

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-13 Observed number

SPF Expected number using Eb

Predicted number from SPF Crash Frequency Crash

aaDT

FIGURE 4-5: Schematic to illustrate the empirical Bayes method (Source: HSIP Manual, 2010)

EB method is applied to calculate average crash frequency are provided an expected crash frequency in Part B of the HSM. For example, or corrected value, which lies if the observed crash frequency in a somewhere between the observed particular site was nine crashes per value and the predicted value from year, the predicted crash frequency the SPF. from the SPF was 6.4 crashes per

year, and the w was 0.3, then Nexpected Mathematically, the expected will be as follows: number of crashes can be written

as a function of the predicted value Nexpected = 0.3 × 6.4 + (1 - 0.3) × 9 from the SPF and the observed = 8.22 crashes per year crashes in the following manner:

Equation 1 We can prioritize sites by calculating the difference between the EB N = w × N + (1 - w) × N expected predicted observed expected crashes at a particular site and the predicted crashes from

Nexpected = expected average crash frequency an SPF. By comparing EB expected for a certain study period crashes at a particular site instead of observed crashes, we account for w = weighted adjustment to be placed possible bias due to RTM. on the SPF prediction (0 < w < 1) The first eight measures presented N = predicted average crash frequency predicted in Table 4-4 do not account for predicted using an SPF for the study possible bias due to RTM. Measure 9 period under the given conditions (probability of specific crash types exceeding threshold proportion) and Nobserved = observed crash frequency at the site over the study period measure 10 (excess proportion of specific crash types) are not affected The weight w is a function of the by RTM unless they are based on

predicted crash frequency (Npredicted) short-term crash history. Measure and a statistical parameter called the 11 (expected average crash frequency overdispersion parameter of the SPF. with EB adjustments), measure Procedures to estimate the expected 12 (EPDO average crash frequency

4-14 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS with EB adjustment), and measure screening. Diagnosis is the process 13 (excess expected average crash of further investigating the sites frequency with EB adjustment) and issues identified from network account for possible bias due to RTM screening. The intent of diagnosis using the EB adjustments. is to identify crash patterns and the factors that contribute to crashes Accounting for crash severity at the identified sites. Thorough The severity of crashes at a location diagnosis can also identify potential can (and should) have a bearing on safety issues that have not yet the priority of the site for safety manifested in crashes. Diagnosis treatment. Three of the measures in often involves a review of the Table 4-4, measure 3 (EPDO average crash history, traffic operations, crash frequency), measure 4 (relative and general site conditions. While severity index), and measure 12 safety professionals could review (EPDO average crash frequency with these data from the office, a field EB adjustment), directly account for visit provides the opportunity to crash severity. Measures 3 and 12 use observe road user behavior and the EPDO method, which converts site characteristics that are not all crashes to a common unit, available in the data. Sometimes, namely property damage only (PDO) safety professionals may also crashes. Using these measures, the conduct a field review at night or analyst assigns points to each crash at other times that crash history based on its crash severity level. has indicated to be of concern. It A PDO crash typically receives one is important to diagnose the cause point and the points increase as the of the problem before developing severity of the crash increases. potential countermeasures, just as a doctor examines symptoms While other measures do not to diagnose an underlying disease explicitly mention severity, analysts before formulating a prescription. can adapt any of the measures to Otherwise, resources may be consider any severity level. For misallocated if a countermeasure example, an analyst could use that does not target the underlying crash frequency and focus on the issues is selected and implemented. frequency of fatal and severe injury crashes to priority rank sites. It is The Haddon Matrix is a framework to important to note that the severity identify possible contributing factors distribution of crashes may be a (e.g., driver, vehicle, and roadway/ function of site characteristics environment) which are cross- including AADT. For example, referenced against possible crash sections with higher AADT values conditions before, during, and after may be associated with lower speeds a crash to identify possible reasons and consequently fewer severe for events. This comprehensive crashes. understanding of crash contributing Step 2. Diagnosis factors is important for the diagnosis of safety problems. An example of Diagnosis is the second step in the Haddon Matrix is presented later the roadway safety management under Countermeasure Selection on process, following network page 4-20.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-15 The HSM recommends that for stop-controlled intersections, diagnosis include the following signalized intersections, and two- parts: lane roads, so the method would be applied separately to the three types JJ A review of safety data of facilities and separately for urban JJ An assessment of supporting and rural environments. Another documentation method would be to investigate sites that experience a gradual or JJ An assessment of field conditions sudden increase in mean collision 21 Safety data review frequency. Following the detailed review of 19 An analyst can conduct a detailed the crash data, the analyst can review of the crash data from police Kononov, J. create collision diagrams, condition reports to identify patterns. This (2002), Identifying diagrams, and crash maps to Locations could involve reviewing the crash with Potential summarize the crash information type, severity, sequence of events, for Collision by location. A collision diagram Reductions: and contributing circumstances. is a tool to identify and display Use of Direct Different visualization tools, such Diagnostics and crash patterns. Many resources, pie charts, bar charts, or tabular Pattern Recognition including the HSM, provide guidance Methodologies, summaries, can be used to display Transportation on developing collision diagrams. various crash statistics. In addition Research Record Examples of collision diagrams are 1784, pp. 153-158. to reviewing descriptive statistics, shown in Figure 4-6 and Figure 4-7. analysts can use various methods Each crash at the site is displayed to identify underlying safety issues according to where it occurred, 20 based on the recognition of crash what type of crash it was, how patterns. Heydecker, B. J., and severe it was, and various other J. Wu (1991), Using the Information One method would be to identify characteristics. An analyst uses in Road Accident locations that have a proportion of symbols to visually represent many Records Proc., 19th of these characteristics. PTRC Summer a specific collision type relative to Annual Meeting, the total collisions that is higher Condition diagrams include a London. than some average or threshold drawing with information about proportion value for similar road the site characteristics including types. Kononov found that looking 21 information about the roadway at the percentage distribution of (e.g., number of lanes, presence Hauer, E. (1996), collisions by collision type can reveal of medians, pedestrian and bicycle Detection of Safety the “existence of collision patterns Deterioration facilities, shoulder information), susceptible to correction” that may in a Series of surrounding land uses, and Accident Counts. or may not be accompanied by the pavement conditions. Condition Transportation overrepresentation in expected Research Record 19 diagrams can be overlaid on top of 1542, 38-43. or expected excess collisions. collisions diagrams to gain further Hauer, E. (1996), Heydecker and Wu originally 20 insight to the crash patterns. Statistical Test proposed this method. The method of the Difference is identical for different location Crash mapping involves the use of between Expected Accident types. However, only similar geographic information systems Frequencies, location types should be analyzed (GIS) to integrate information Transportation from the roadway network with Research Record together because collision patterns 1542, 24-29. will naturally differ. For example, information from geocoded crash the collision patterns are different data. If the geocoded crash data are

4-16 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS FIGURE 4-6: Example Collision Diagram at an Intersection

FIGURE 4-7: Example Collision Diagram at a Ramp

accurate, then crash mapping can Assess field conditions provide valuable insights into crash locations and crash patterns. Field observations are useful for supplementing crash data and can Assess supporting help the analyst understand the documentation behavior of drivers, pedestrians, and bicyclists. The first stage of This step involves a review of the field investigation should documented information about be an on-site examination of a the site along with interviews of road user’s experience. Those local transportation professionals conducting the assessment should to obtain additional perspectives travel through the site at different on the safety data review from times of the day using different the previous step. Examples of modes of transportation (e.g., supporting documentation include driving, walking, and bicycling). traffic volumes, construction plans Assessors should observe the mix and design criteria, photos and of vehicle traffic and other road maintenance logs, weather patterns, users. They should also observe and recent traffic studies in the area. traffic movements, conflicts, and

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-17 ROAD SAFETY AUDIT TRADITIONAL SAFETY REVIEW

Safety review team within the project team Independent, multi-disciplinary team with only safety and/or design experience

Considers all potential road users (pedestrians, Often concentrates only on motor vehicles bicyclists, motor vehicles, transit users)

Accounts for road user capabilities Safety reviews do not normally and limitations consider human factor issues

Always generates a formal report Often does not generate a formal report

Often does not generate a formal Always generates a formal response report response report

TABLE 4-5: Differences between Road Safety Audit and Traditional Road Safety Review (Source: FHWA)

operating speeds. Those conducting JJ What elements of the road may the field review could determine present a safety concern, and to whether the road and intersection what extent, to which road users, characteristics are consistent and under what circumstances? with driver expectation and if JJ What opportunities exist to roadside recovery zones are clear eliminate or mitigate identified and traversable. safety concerns?

Road safety audits The multidisciplinary audit team One method to assess field consists of people who represent conditions is a road safety audit different areas of expertise, such as (RSA). This is the formal safety engineering (e.g., design, traffic, performance examination of and maintenance), law enforcement, 22 an existing or future road or safety educators, public officials, “Road Safety Audits intersection by an independent, community traffic safety advocates, (RSA),” accessed and others. Any phase of project August 7, 2013, multidisciplinary team. An RSA http://safety.fhwa. qualitatively estimates and reports development (planning, preliminary dot.gov/rsa/ on existing and potential road safety engineering, design, construction) issues and identifies opportunities and any sized project from minor for safety improvements for all intersection and roadway retrofits road users. FHWA encourages to mega-projects are eligible for States, local jurisdictions and tribal an RSA. governments to integrate RSAs into Most State DOTs have established the project development process for safety review processes. However, new roads and intersections and to RSAs and a traditional safety reviews conduct RSAs on existing ones. are different. Table 4-5 shows the The purpose of an RSA is to answer difference between an RSA and a the following questions: traditional safety review.22

4-18 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS factors. Analysts can use the Haddon International Road Matrix to identify human, vehicle, Assessment Programme and roadway factors contributing The International Road Assessment to the frequency and severity of Programme (iRAP) conducts safety crashes prior to, during, and after inspections on high-risk roads in more the crash event. Then, analysts than 70 countries. The iRAP inspectors can identify targeted reactive and perform a detailed road survey, focusing proactive countermeasures to on road attributes that are known to be associated with crash risk. These include address or mitigate the underlying intersection design, number of lanes, contributing factors for the given roadside hazards, and provisions for site. Chapter 6 of the 1st edition of pedestrian crossings. The inspectors the HSM provides further discussion use these data to develop a star rating, of the Haddon Matrix. which reflects the level of safety of the road, and provide detailed feedback to The Haddon Matrix is comprised the government agency in the form of an of nine cells to identify human, assessment report. iRAP also provides a Road Safety Toolkit, which helps vehicle, and roadway factors engineers, planners, and policy makers contributing to the target crash develop safety plans for all road users.23 type or severity outcome before, 23 during, and after the crash. Pre- crash factors speak to the factors http://www.irap.net/ Step 3. Countermeasure or actions prior to the crash that http://toolkit.irap. selection contributed to the occurrence of the org/ crash. Crash factors speak to those After diagnosing the safety factors or actions that occurred at issues at the site, analysts select the moment of the crash. Post-crash countermeasures to address factors speak to factors that come the contributing factors for into play after the crash that affect observed crashes. The first part the severity of the injuries or speed 24 of countermeasure selection is of response. Examples of human to identify countermeasures to factors include fatigue, inattention, Haddon, W., Jr. target the underlying safety issues. age, and failure to wear a seat belt. (1972). A logical framework for Analysts can use tools like the Vehicle factors include bald tires, categorizing Haddon Matrix and resources like airbag operations, and worn brakes. highway safety phenomena and the NCHRP Report 500 series to Examples of roadway factors include activity. Journal of identify targeted countermeasures pavement friction, weather, grade, Trauma 12: 193–207. to address or mitigate underlying and limited sight distance. contributing factors. Table 4-6 is an example application 25 Identifying contributing factors of the Haddon Matrix from the Highway Safety Improvement Susan Herbel, The Haddon Matrix is a tool Program (HSIP) Manual for crashes Lorrie Laing, Colleen McGovern 25 originally developed for injury in an urban area. The top-left (2010), Highway prevention, but it is directly cell identifies driver behaviors or Safety Improvement Program (HSIP) applicable to highway safety in characteristics that may contribute Manual, FHWA- both diagnosis and countermeasure to the likelihood or the severity of SA-09-029, 24 Federal Highway selection. The Haddon Matrix is a collision, such as poor vision or Administration, useful to gain a comprehensive reaction time, alcohol consumption, Washington, DC. understanding of crash contributing speeding, and risk taking. These

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-19 factors should be considered when important to stay informed of the 26 selecting countermeasures. For available resources and tools.26 Highway Safety example, based on these human Improvement Some of the most useful resources Program Manual. factors, successful countermeasures and tools for countermeasure Federal Highway may be those that improve visibility Administration, guidance and selection are listed or reduce speeding. The matrix in its Washington, D.C., below (alphabetically): 2010, Chapter 3 entirety provides a range of potential issues that can be addressed through JJ Bicycle Safety Guide and a variety of countermeasures Countermeasure Selection System including education, enforcement, (BIKESAFE, www.pedbikesafe. engineering, and emergency org/bikesafe) – This resource response solutions. provides practitioners with the latest information available Countermeasure for improving the safety and resources and tools mobility of those who bike. The online tools provide the Diagnosing a roadway safety user with a list of possible problem and identifying effective engineering, education, or countermeasures is a skill enforcement treatments to developed through education, improve bicycle safety and/or training, research, and experience. mobility based on user input Many resources are available to about a specific location. help transportation professionals analyze and develop JJ Countermeasures That Work: A countermeasures. Since the Highway Safety Countermeasure transportation field continuously Guide for State Highway Safety generates new knowledge and Offices – This document serves countermeasure approaches, it is as a basic reference to help state

VEHICLE/ PHYSICAL SOCIO- PERIOD HUMAN EQUIPMENT ENVIRONMENT ECONOMIC

PRE- Poor vision or Failed brakes, Narrow Cultural norms CRASH reaction time, missing lights, shoulders, permitting alcohol, speeding, lack of warning ill-timed signals speeding, red risk taking systems light running, DUI

CRASH Failure to Malfunctioning Poorly designed Lack of use occupant safety belts, guardrails vehicle design restraints poorly engineered regulations air bags

POST- High Poorly designed Poor emergency Lack of support CRASH susceptibility, fuel tanks communication for EMS and alcohol systems trauma systems

TABLE 4-6: Haddon Matrix for crashes in an urban area (Source: HSIP Manual)

4-20 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS highway safety offices (SHSOs) JJ Highway Safety Manual (www. select effective, evidence-based highwaysafetymanual.org) – countermeasures for traffic This document provides safety problem areas related science-based knowledge to user behaviors, such as and tools to conduct safety alcohol-impaired and drugged analyses, allowing for safety driving, seat belts and child to be quantitatively evaluated restraints, and aggressive alongside other transportation 27 27 driving and speeding. performance measures, such as traffic operations, Goodwin, A., JJ Crash Modification Factors Thomas, L., Kirley, Clearinghouse (www. environmental impacts, B., Hall, W., O’Brien, and construction costs. N., & Hill, K. (2015). cmfclearinghouse.org) – This Countermeasures website offers transportation that work: A JJ National Cooperative Highway highway safety professionals a central, online Research Program (NCHRP) countermeasure repository of crash modification Report 500 Series (safety. guide for State factors (CMFs) that indicate the highway safety transportation.org/guides.aspx) offices, Eighth safety effect on crashes due to edition. (Report No. – This resource is a collection infrastructure improvements. DOT HS 812 202). of 23 reports in which relevant Washington, DC: The website also provides National Highway information is assembled into additional information and Traffic Safety single concise volumes, each Administration. resources related to CMFs. Accessed February This site is funded by FHWA. pertaining to specific types 2017 at www.nhtsa. of highway crashes (e.g., gov/staticfiles/ JJ FHWA Proven Countermeasures nti/pdf/812202- run-off-the-road, head-on) Countermeasures (safety.fhwa.dot.gov/ or contributing factors (e.g., ThatWork8th.pdf provencountermeasures) – aggressive driving) related FHWA regularly compiles a list to behaviors, vehicles, and of countermeasures that have roadways. Countermeasures been shown to be effective in are categorized as proven, reducing crashes but have yet tried, and experimental. to be widely applied on a national basis. JJ Pedestrian Safety Guide and Countermeasure Selection System JJ Handbook for Designing Roadways (PEDSAFE, www.pedbikesafe. for the Aging Population (safety. fhwa.dot.gov/older_users/ org/pedsafe) – This resource provides practitioners with the handbook) – This FHWA guide provides practitioners with a latest information available 28 for improving the safety and practical information source that Brewer, M., D. links aging road user performance mobility of those who walk. Murillo, A. Pate The online tools provide the (2014). Handbook to highway design, operational, for Designing and traffic engineering features. user with a list of possible Roadways for the This handbook supplements engineering, education, or Aging Population, Report No. existing standards and guidelines enforcement treatments to FHWA-SA-14-015, in the areas of highway improve pedestrian safety and/ Federal Highway Administration, geometry, operations, and or mobility based on user input Washington, D.C. traffic control devices.28 about a specific location.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-21 Identifying and selecting 29 Guidance on CMF application countermeasures www. FHWA provides an extensive selection cmfclearinghouse. org After identifying potential of guidance on selecting and applying countermeasures to target CMFs through the CMF Clearinghouse the underlying issues, safety (www.cmfclearinghouse.org). They present answers to frequently asked professionals must estimate the questions, such as “How can I apply safety impact of countermeasures, multiple CMFs?” and “How do I choose individually and in combination. It between CMFs in my search results that is important to consider positive and have the same star rating but different negative safety impacts. Subsequent CMF values?” The website also houses steps of the roadway safety an archive of annual webinars in which experienced CMF users talk about management process (i.e., economic issues related to applying CMFs in appraisal and project prioritization) real world situations. include the consideration of other parameters, such as constructability, environmental impacts, and cost. then that countermeasure is The agency that will be making the expected to increase crashes. final decision on countermeasure JJ A CMF of 1.0 implies that a selection should make sure to countermeasure will not have coordinate with other safety any effect on safety. partners to ensure that the countermeasure is appropriate for all For example, if the expected number parties. For example, a DOT should of crashes without a countermeasure coordinate with law enforcement is 5.6 crashes per year, and the CMF and emergency response to make for the particular countermeasure sure that a proposed engineering is 0.8, then the expected number of installation will interfere with crashes with the countermeasure is: enforcement activities or impede 5.6 crashes per year x 0.8 = emergency responders. 4.48 crashes per year For infrastructure improvements, It is important to recognize that CMFs associated with different some countermeasures may decrease countermeasures provide a some types of crashes but increase mechanism for determining other types. For example, installing the safety effect of different a traffic signal would be expected to countermeasures. A CMF is a decrease severe collisions, such as multiplicative factor used to right angle and left turn crashes, but compute the expected number of it would be expected to increase less crashes after implementing a given severe crashes, such as rear ends. countermeasure at a specific site. The CMF Clearinghouse and the first JJ If the CMF for a particular edition of the HSM provide CMFs treatment is less than 1.0, then for a variety of countermeasures.29 that countermeasure is expected Only those CMFs that passed a set to reduce crashes. of inclusion criteria based on quality JJ If the CMF for a particular and reliability were included in the treatment is greater than 1.0, HSM. The CMFs in the clearinghouse

4-22 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS are provided for any published critical for practitioners to use study, regardless of quality, and engineering judgment when a CMF are continuously updated based on is not available for the situations the latest research. The CMFs in encountered as there are some cases the clearinghouse are reviewed and for which a CMF that was developed given a star quality rating ranging for different conditions might be the from one to five stars, based on the best available. quality of the study. Higher stars imply a better quality CMF. Step 4. Economic appraisal

CMFs should be applied to situations An economic appraisal of alternative that closely match those from countermeasures should be which the CMF was developed. conducted to ensure that safety Several variables can be used to funds are being used as efficiently match a CMF to a given scenario as possible. This appraisal helps including roadway type, area type, transportation agencies achieve segment or intersection geometry, their desired safety performance the intersection traffic control, and fastest and at the lowest possible traffic volume. However, it is cost. An agency can compare

Calculating benefits due to crash reduction

A city has a stop-controlled intersection in the calculation of the crash reduction with an expected crash frequency of 10 benefit.30 This CMF applies only to serious crashes per year, consisting of one A-injury and minor injury crashes, so they do not 30 crash, one B-injury crash, two C-injury use it to estimate any reduction to fatal or Rodegerdts et al., crashes, and six PDO crashes. PDO crashes (see note). “NCHRP Report 572: Applying The city is considering installing a They multiply the CMF by the expected Roundabouts in roundabout at the intersection. Based on crashes before roundabout installation the United States.” a search of the FHWA CMF Clearinghouse, to determine the expected crashes after Washington, D.C., they decide that they will use a CMF of 0.19 installation: Transportation Research Board, National Research A- B- C- Council, (2007) CRASH SEVERITY FATAL INJURY INJURY INJURY PDO

Expected Crashes per Year 0 1 1 2 6 I before Roundabout

II CMF N/A 0.19 0.19 0.19 N/A

Expected Crashes per Year 0 0.19 0.19 0.38 6 III after Roundabout (I x II)

Crash reduction benefit (I IV minus III) 0 0.81 0.81 1.62 0

Thus, the benefit of a roundabout NOTE: A roundabout would also likely bring installation is expected to be a reduction of a reduction to fatal and PDO crashes (i.e., 0.81 A-injury crashes, 0.81 B-injury crashes, additional CMFs could be incorporated), but and 1.62 C-injury crashes per year. the example has been simplified to a single CMF for illustration purposes.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-23 the benefits expected from the INJURY COMPREHENSIVE countermeasure to the estimated SEVERITY LEVEL CRASH COST costs of the countermeasure. Fatality (K) $4,008,900 Some safety countermeasures have a higher-cost value than others. Disabling Injury (A) $216,000 Geometric improvements to the Evident Injury (B) $79,000 road, such as straightening a tight curve to reduce run-off-road Fatal/Injury (K/A/B) $158,200 crashes, tend to be very expensive. Installing a curve warning sign Possible Injury (C) $44,900 and in curve delineation may address the same problem, but PDO (O) $7,400 at a much lower cost. Although both countermeasures address the TABLE 4-7: Crash Costs by Severity Level same problem, the actual safety in the Highway Safety Manual, 1st ed. benefit may not be the same. Safety professionals take the relative costs and benefits into consideration crashes reduced. This monetary when prioritizing among value is also called the crash cost. countermeasures. Part of calculating Crash costs are based on costs to the cost of a countermeasure society, such as lost productivity, is considering how those costs medical costs, legal and court costs, vary over time, while taking into emergency service costs, insurance consideration any maintenance administration costs, congestion costs and long term effectiveness. costs, property damage, and 31 workplace losses.31 Estimating benefits Blincoe, L. J., Miller, The benefit from the T. R., Zaloshnja, E., and Lawrence, B. The primary benefit of a countermeasure is the sum of the A. The economic countermeasure is a reduction crash costs for crashes prevented by and societal impact of motor in crash frequency or severity. the countermeasure. Assigning costs vehicle crashes, To estimate the safety benefits, to crashes is a topic that is under 2010. (Revised), constant discussion and revision National Highway a safety professional should use Traffic Safety CMFs, such as those discussed nationwide. States differ widely Administration, in the countermeasure selection in the dollar amount that they Report No. DOT HS 812 013, Washington, step. CMFs can be applied to the assign to crashes, though all States DC, May 2015. actual crashes or expected crashes apply higher values to more severe based on the EB method. Expected crashes. The CMF Clearinghouse crashes are preferred because they provides a synthesis of crash costs 32 account for possible bias due to RTM. that are used by various States.32 The estimated change in crashes http://www. Additionally, the first edition of the cmfclearinghouse. represents the expected benefit from HSM provided a list of crash costs by org/resources_ the countermeasure. servlifecrash severity level (Table 4-7). However, costguide.cfm For each proposed countermeasure, since the publication of the first the change in crash frequency and/ HSM in 2010, the USDOT has issued or severity needs to be converted periodic recommendations that to monetary value, based on the dramatically raised the values. For monetary value of the type of instance, the monetary value of a

4-24 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS fatal crash was listed as $4 million in similar countermeasures. Table 4-8 33 the HSM, but recommended as over illustrates the types of startup and $9 million in a 2013 policy memo ongoing costs that would be incurred Trottenberg, Polly, and Robert 33 from USDOT. for various countermeasures. Rivkin, “Revised Departmental Although countermeasures are Service life Guidance 2013: primarily expected to reduce Treatment of the Value of Preventing crashes, there might be other Another important consideration Fatalities and benefits, including reduced travel when calculating the benefits Injuries,” and costs of a countermeasure USDOT Office of times or lower fuel consumption. For the Secretary of example, a roundabout can decrease is the length of time that the Transportation, 2013. total delay at an intersection if countermeasure will last. This is referred to as the service life. applied and configured properly. Countermeasures, such as road An AASHTO publication provides edgelines or pavement reflectors, guidance on estimating these other will have a much shorter service 34 non-safety benefits.34 life (e.g., three to five years) than User and Non-User Estimating costs countermeasures, such as traffic Benefit Analysis for signal installation or sidewalk Highways, American Association of The costs of the proposed construction (e.g., 20 years or State Highway countermeasure include the startup more). Many States have a standard Transportation Officials, September cost and the ongoing operational and list of the service life values used 2010 maintenance costs. These costs can for common countermeasures. usually be estimated based on costs The CMF Clearinghouse provides a of materials, labor cost per person- survey of service life values used by hour, cost of additional right-of- various States for many different 35 way, and past experience with countermeasures.35 http://www. cmfclearinghouse. Calculating monetary benefit of crash reduction org/resources_ servlifecrash The previous example showed that a city USDOT, and experiences of other cities costguide.cfm calculated a crash savings of 0.81 A-injury and States and determined a standard set crashes, 0.81 B-injury crashes, and 1.62 of crash costs they will use for all benefit/ C-injury crashes per year by installing cost calculations. They apply these costs a roundabout. The city has examined to determine the monetary benefit of the guidance from the HSM, guidance from expected crash reductions:

A- B- C- CRASH SEVERITY FATAL INJURY INJURY INJURY PDO

IV Crash Reduction Benefit 0 0.81 0.81 1.62 0

V This City’s Standard Crash Cost $5 mil $400,000 $100,000 $60,000 $10,000

Monetary benefit of crash VI reduction (IV x V) 0 $324,000 $81,000 $97,200 0

Thus, the city expects a total monetary benefit of $324,000+$81,000+$97,200 = $502,000 per year due to reduction in crashes.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-25 ONGOING COST COUNTERMEASURE STARTUP COST DURING SERVICE LIFE

Install curve Low – sign material, minimal None warning sign labor for installation

High – Design plan, purchase Low – maintenance of of additional right-of-way, Install roundabout grass and decorative material, labor, traffic control vegetation during construction

High – Timing plan, material, Moderate – electricity, Install traffic signal labor for installation, traffic bulb replacements, repairs, control during construction modifications to timing

TABLE 4-8: Examples of Countermeasure Costs

The service life is used in the calculation of the present value Calculating the present value of the benefits and costs of the of a crash reduction benefit proposed countermeasure. The From the previous example, the city calculation of present value includes plans to install a roundabout and a discount rate that reflects the time expects to see a benefit from crash value of money (i.e., present dollars reductions resulting in savings of $502,000 per year. They estimate that the are worth more than future dollars). roundabout will have a service life of 20 Present value of countermeasure years and they determine that a discount benefits is calculated as follows: rate of 5% is appropriate. They calculate the present value of benefits as: (1+i)y-1 PV = A × (1+0.05)20-1 i×(1+i)y PV = $502,000 × 0.05×(1+0.05)20 PV = present value of benefits = $6,256,030 A = annual benefit (i.e., monetary value of crashes prevented)

i = discount rate costs, the final present value must also include the startup cost in the y = service life of countermeasure year of installation (see examples Calculating present value in this way in Table 4-8). 36 assumes a uniform annual benefit. Methods for Herbel, Susan, The HSIP Manual demonstrates Lorrie Laing, Colleen how to calculate present value if the economic appraisal McGovern, Highway benefits or costs each year are not Safety Improvement 36 There are several methods for Program the same. (HSIP) Manual, using the values of estimated Federal Highway The present value of annual costs benefits and costs to evaluate the Administration, (i.e., operational and maintenance economic effectiveness of safety FHWA-SA-09-029, January 2010 costs) can be calculated in the same improvement projects at a particular manner as for benefits. However, for site. In particular, these methods

4-26 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS are useful in situations where a The formula for NPV is: safety professional is considering NPV = PVB − PVC several alternatives and desires to choose the countermeasure with the PVB = Present value of benefits greatest benefit for the cost. PVC = Present value of costs The HSIP Manual contains guidance on three methods - net present A countermeasure will result in a value, benefit/cost ratio, and cost net benefit if the NPV is greater than effectiveness index.37 Net present zero. Table 4-9 summarizes the 37 value (NPV) is generally regarded NPV calculations of four alternative Herbel, Susan, as the most economically countermeasures. Lorrie Laing, Colleen appropriate method, though the McGovern, Highway For Alternative A, the NPV can be Safety Improvement other two methods have certain calculated as follows: Program advantages, as discussed below. (HSIP) Manual, Federal Highway The following sections provide NPV = $1,800,268 − $500,000 Administration, quoted guidance from the HSIP = $1,300,268 FHWA-SA-09-029, Manual on economic appraisal. January 2010. The same calculation is performed Net Present Value for the other three countermeasure alternatives, and rank each The NPV method, also called the net present worth (NPW) method, countermeasure based on its NPV. expresses the difference between the As shown, all four alternatives present values of benefits and costs are economically justified with a of a safety improvement project. NPV greater than zero. However, The NPV method has two basic Alternative B has the greatest NPV functions: 1) determining which for this site based on this method. countermeasure(s) is/are most Benefit/Cost Ratio and Analysis cost efficient based on the highest NPV and 2) determining whether The benefit/cost ratio (BCR) is a countermeasure’s benefits are the ratio of the present value of a greater than its costs (i.e., the project’s benefits to the present project has a NPV greater than zero). value of a project’s costs.

PRESENT PRESENT NET ALTERNATIVE VALUE OF VALUE OF PRESENT ALTERNATIVE COUNTERMEASURE BENEFITS (I) COSTS (II) VALUE (I-II) RANK

A $1,800,268 $500,000 $1,300,268 3

B $3,255,892 $1,200,000 $2,055,892 1

C $3,958,768 $2,100,000 $1,858,768 2

D $2,566,476 $1,270,000 $1,296,476 4

TABLE 4-9: Net Present Value (Source: HSIP Manual, Chapter 4)

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-27 The formula for BCR is: cost analysis, transportation professionals compare all of BCR = PVB / PVC the benefits associated with PVB = Present value of benefits a countermeasure (e.g., crash reduction), expressed in monetary PVC = Present value of costs terms, to the cost of implementing Table 4-10 shows an example the countermeasure. A benefit/cost of using BCR to prioritize four analysis provides a quantitative alternatives. measure to help safety professionals prioritize countermeasures or A project with a BCR greater than 1.0 projects and optimize the return indicates that the benefits outweigh on investment. the costs. However, the BCR is not applicable for comparing various Cost-Effectiveness Index countermeasures or multiple In situations where it is not projects at various sites; this requires an incremental benefit/cost analysis. possible or practical to monetize countermeasure benefits, An incremental benefit/cost analysis transportation professionals can provides a basis of comparison of the use the cost-effectiveness index benefits of a project for the dollars method in lieu of the NPV or BCR. invested. It allows the analyst to Cost-effectiveness is simply the compare the economic effectiveness amount of money invested divided of one project against another; by the crashes reduced. The result however, it does not consider budget is a number that represents the constraints. Optimization methods cost of the avoided crashes of are best for prioritizing projects a certain countermeasure. The based on monetary constraints. countermeasure with the lowest An in-depth explanation of value is the most cost-effective and incremental benefit/cost analysis therefore ranked first. and an example is provided in Chapter 4 of the HSIP Manual. Cost-Effectiveness Index = PVC/CR

When conducting a benefit/ PVC = Present value of project cost

PRESENT PRESENT BENEFIT/ ALTERNATIVE VALUE OF VALUE OF COST ALTERNATIVE COUNTERMEASURE BENEFITS (I) COSTS (II) RATIO (I/II) RANK

A $1,800,268 $500,000 3.6 1

B $3,255,892 $1,200,000 2.7 2

C $3,958,768 $2,100,000 1.9 4

D $2,566,476 $1,270,000 2.0 3

TABLE 4-10: Example of Benefit/Cost Ratio Prioritization (Source: HSIP Manual, Chapter 4)

4-28 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS PRESENT TOTAL COST- ALTERNATIVE VALUE OF CRASH EFFECTIVE- ALTERNATIVE COUNTERMEASURE COSTS REDUCTION NESS INDEX RANK

A $500,000 43 $11,628 1

B $1,200,000 63 $19,048 3

C $2,100,000 70 $30,000 4

D $1,270,000 73 $17,397 2

TABLE 4-11: Cost-Effectiveness Index (Source: HSIP Manual, Chapter 4)

CR = Total crash reduction therefore ranked first. Alternative A is ranked first, since it has the The Cost-Effectiveness Index lowest cost associated with each is a simple and quick method crash reduction. that provides an indication of a project’s value. Transportation The above example uses the number professionals can use this formula of crashes to determine the cost- and compare its results with other effectiveness index. Transportation safety improvement projects. The professionals can use this same Cost-Effectiveness Index method, method using EPDO crash numbers, however, does not account for value which has the advantage of differences between reductions in considering severity. fatal crashes compared to injury 38 crashes, and whether a project is Step 5. Project prioritization economically justified.38 Highway Safety If a transportation agency Improvement Program Manual. Table 4-11 summarizes the is considering installing Federal Highway calculations using the cost- countermeasures at one or more Administration (Washington D.C., effectiveness index method to rank sites out of a group of potential 2010), Chapter 4 alternative countermeasures, given sites, they will need to prioritize the present value of the costs and which projects they will implement. the total crash reduction. Ideally, the agency would implement all projects that bring a safety For Alternative A, calculate the cost- benefit (e.g., all those with a NPV effectiveness index as follows: greater than zero or a BCR greater Cost-effectiveness index = 500,000/43 than one). However, all agencies = 11,628 work within a limited budget and must prioritize where safety funds Calculate the Cost-Effectiveness are spent. Index for the remaining alternatives and rank each countermeasure based The agency can use steps 1 through on its Cost-Effectiveness Index 4 of this process to determine value. With this method, the lowest which countermeasure(s) would be index is the highest priority and used at each potential treatment

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-29 site and to conduct an economic Incremental BCR = appraisal of the expected effect of (Benefit of Project A − Benefit of Project B) the countermeasure. The next step is to determine project priorities. (Cost of Project A − Cost of Project B) The HSM discusses how projects can be prioritized by economic If the incremental BCR is greater effectiveness, incremental than 1.0, the project with the benefit/cost analysis, or various higher cost is compared to the next optimization methods. project on this list; however, if the Prioritizing by incremental BCR is less than 1.0, the project with the lower cost is economic effectiveness compared to the next project on the list. This process is repeated and the Projects can be prioritized by ranking project selected in the last pairing projects or project alternatives is the considered the best economic by the economic appraisal values investment. produced in step 4. An agency might select those projects with the Prioritizing by highest NPV, the highest BCR, or the highest cost effectiveness index. optimization methods When using NPV the goal of a safety Optimization methods take into professional should be to implement account certain constraints when all projects that have an NPV prioritizing projects. Linear greater than zero, since each one programming, integer programming, brings a safety benefit. However, and dynamic programming (refer this is not possible since funds are to Chapter 8, Appendix A, HSM, limited, thus the goal should be to 2010) are optimization methods implement the group of projects consistent with an incremental that have the greatest combined benefit/cost analysis, but they also NPV when added together (NPV is account for budget constraints in an additive property). Maximizing the development of the project the NPV of a group of projects is list. These optimization methods different from prioritizing projects are more likely to be incorporated with high NPV. In other words, it into a software package, rather may be best to implement numerous than manually calculated. Multi- low cost projects with low NPV than objective resource allocation is one high cost project with a high another optimization method. NPV – but not higher than the NPV It incorporates nonmonetary of all the low cost projects added up. elements (including decision factors not related to safety) into the Prioritizing by incremental prioritization process. benefit/cost analysis Safety professionals may use This method involves ranking all software applications to select projects with benefit cost ratio and rank countermeasures. The 39 greater than 1.0 in increasing order SafetyAnalyst tool from AASHTO

http://www. of their estimated cost. An analyst includes economic appraisal safetyanalyst.org/ calculates an incremental BCR and priority ranking tools.39 The as such: economic appraisal tool calculates

4-30 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS 40

Gross, F., B. Persaud, and C. Lyon (2010), A Guide for Developing Quality Crash Modification Factors, Report FHWA-SA-10-032, Federal Highway Administration, Washington, D.C. Available at http://www. the BCR and other metrics for a set for the countermeasure, which cmfclearinghouse. org/resources_ of countermeasures. The priority- quantifies the effect on crashes (see develop.cfm. ranking tool ranks proposed CMF discussion in Step 4). Accessed July 2016. improvement projects based on Two documents entitled A Guide the benefit and cost estimates to Developing Quality Crash from the economic appraisal tool. 41 Modification Factors40 (from FHWA) The priority-ranking tool can also and Recommended Protocols for Carter, D., R. determine an optimal set of projects Srinivasan, F. Developing Crash Modification to maximize safety benefits. Gross, and F. Factors41 (from NCHRP) provide Council (2012), guidance on the different methods Recommended Step 6. Safety Protocols for for conducting evaluations. The Developing Crash effectiveness evaluation following is an overview of study Modification Factors, Prepared Once a countermeasure has been designs and methods for conducting as part of NCHRP evaluations. Project 20-07 (Task implemented at a site, or group of 314), Washington, sites, it is important to determine Categories of Study Designs D.C. Available whether it was effective in at http://www. cmfclearinghouse. addressing the safety problem. For Study designs fall into two broad org/resources_ a safety professional to evaluate the develop.cfm. categories - experimental and Accessed July 2016. countermeasure, he or she must observational. Experimental studies determine how the countermeasure are conducted when sites are affected the frequency, type, and selected at random for treatment. 42 severity of crashes. For example, There is general consensus that did the installation of a roundabout experimental studies are the most Elvik, R. (2011a), Assessing Causality 42 reduce the frequency of angle rigorous way to establish causality. in Multivariate crashes? If so, by how much? Did In contrast, observational studies Accident Models, Accident Analysis it cause an increase to any other are conducted when sites are not and Prevention, Vol. types of crashes? A countermeasure selected as part of an experiment but 43, pp. 253-264. evaluation can result in a CMF selected for other reasons including

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-31 safety. Truly experimental studies from a before-after study. In a are not common in road safety typical before-after study, an partly because of potential liability analyst deals with same roadway considerations (i.e., a random unit located in a particular place, selection may result in an agency most likely used by the same road being held liable for failing to treat users during the before and after some sites that have demonstrated period. Since most of these factors high crash history). Observational can be assumed to be constant or studies are more common in almost constant in the before and countermeasure evaluations after periods, they are less likely because most transportation to cause significant biases. On agencies prioritize installation sites the other hand, “cross-sectional based on some kind of past safety studies compare different roads, performance (see Step 1, Network used by different road users, located Screening). at different places and subject to different weather conditions. Observational studies of Besides, these roads will differ in countermeasures can be broadly very many other ways that are not classified into cross-sectional measured.”43 However, there are 43 studies and before-after studies. In issues in both types of studies that cross-sectional studies, an analyst Elvik, R. (2011a), need to be addressed, and they are Assessing Causality compares a group of sites with a in Multivariate briefly discussed below. Accident Models, certain feature to a group of sites Accident Analysis without that feature. For example, Cross sectional studies and Prevention, Vol. an analyst might compare the 43, pp. 253-264. safety performance of a group of Analysts use cross-sectional studies stop-controlled intersections to to compare the safety of a group of that of a group of yield-controlled sites with a feature with the safety of intersections to determine the effect a group of sites without that feature. of the type of traffic control on The resulting CMF can be derived by crashes. Cross-sectional studies can taking the ratio of the average crash also be thought of as “with/without” frequency of sites with the feature studies. In before-after studies, an to the average crash frequency of analyst takes a group of sites and sites without the feature. For this compares the safety performance in method to work, the two groups the period before a countermeasure of sites should be similar in their is implemented to the period after characteristics except for the the countermeasure is implemented. feature. In practice, this is difficult For example, in a before-after study, to accomplish and multiple variable an analyst could evaluate the effect regression models are used. These of converting a stop-controlled cross-sectional models are also intersection to a roundabout by called SPFs. The coefficients of the comparing safety data before the variables from these equations are roundabout conversion to the safety used to estimate the CMF associated data afterwards. with a treatment.

CMFs that result from cross- Guidance from FHWA on developing sectional studies are not considered CMFs says that “the basic issue to be as robust as those resulting with the cross-sectional design is

4-32 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Using cross-sectional modeling to calculate a CMF for widening shoulders

A CMF can be obtained from a cross estimated to predict the number of crashes sectional model. Suppose the intent is per mile per year on rural two-lane roads in to estimate the CMF for shoulder width mountainous roads with paved shoulders based on the following SPF, which was (Appendix B of Srinivasan and Carter, 201144): 44 AADT AADT Y = exp [ 0.8727 + 0.4414 × ln( ) + 0.4293 × ( ) -0.0164 × SW ] 10000 10000 Srinivasan, R. and D. Carter (2011), Where, AADT is the annual average daily be estimated as the ratio of the predicted Development of traffic and SW is the width of the paved number of crashes when the shoulder Safety Performance shoulder in feet. If the intent is to estimate width is six feet to the predicted number Functions for North the CMF of changing the shoulder width of crashes when the shoulder width is Carolina, Report FHWA/NC/2010- from three to six feet, then the CMF can three feet: 09, Submitted to AADT AADT NCDOT, December exp [ 0.8727 + 0.4414 × ln( ) + 0.4293 × ( ) -0.0164 × 6 ] 2011. 10000 10000 CMF = exp [ 0.8727 + 0.4414 × ln( AADT ) + 0.4293 × ( AADT ) -0.0164 × 3 ] 10000 10000 This ratio simplifies to: of possible values (i.e., the confidence interval). This range can be calculated by CMF = exp [-0.0164 × (6-3) ] = 0.952 using the standard deviation of the CMF. In This CMF of 0.952 indicates that changing order to estimate the standard deviation, the shoulder width from three to six feet the standard error of the coefficient of SW would be expected to reduce crashes (since is needed, which was reported to be 0.0015 the CMF is less than 1.0). Specifically, the in the original study. The high and low ends expected change in crashes would be a of the confidence interval are calculated 4.8% reduction (1.0 – 0.952 x 100 = 4.8). using -0.0164+0.0015, and then using -0.0165-0.0015, and the difference between However, it is important to recognize that the two is divided by two. The equation is this CMF of 0.952 is the midpoint in a range given below:

exp [-0.0164+0.0015 × (6-3) ] - exp [-0.0164-0.0015 × (6-3) ] StDev(CMF) = = 0.004 2 The approximate 95% confidence confidence interval is below 1.0, the CMF is interval for the CMF is (0.952-1.96×0.004, statistically significant, thereby indicating 0.952+1.96×0.004), which translates to a that widening the shoulder from three to six range of 0.944 to 0.960. Since the entire 95% feet is very likely to reduce crashes. 45

Gross, F., B. Persaud, and that the comparison is between two issue is not completely resolved C. Lyon (2010), distinct groups of sites. As such, since it is difficult to properly A Guide for Developing Quality the observed difference in crash account for unknown, or known Crash Modification Factors, Report experience can be due to known or but unmeasured, factors. For unknown factors, other than the FHWA-SA-10-032, these reasons, caution needs to Federal Highway feature of interest. Known factors, Administration, be exercised in making inferences such as traffic volume or geometric Washington, about CMFs derived from cross- D.C. Available characteristics, can be controlled at http://www. for in principle by estimating a sectional designs. Where there are cmfclearinghouse. sufficient applications of a specific org/resources_ multiple variable regression model develop.cfm. and inferring the CMF for a feature countermeasure, the before-after Accessed July 2016. from its coefficient. However, the design is clearly preferred.”45

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-33 46

Gooch, J.P., Gayah, V.V., and Donnell, E.T. (2016), Quantifying the Safety Effects of Horizontal Curves on Two-Way, Two- Lane Rural Roads, Accident Analysis and Prevention, Vol. 92, pp. 71-81.

47

Holmes, W.M., (2013). Using Propensity Scores in Quasi-Experimental Designs. SAGE Publications.

48

Wood, J., Porter, R., (2013). Safety impacts One way to account for some of Other types of cross-sectional of design exceptions on non-freeway the limitations of cross-sectional methods include case control and segments. Transport. regression models is to use the cohort methods. “Case-control Res. Rec.: J. Transport. Res. Board 2358, 29–37. propensity scores-potential studies select sites based on outcome outcome method. This method status (e.g., crash or no crash) and uses the “individual traits of a then determine the prior treatment 49 site to calculate its propensity (or risk factor) status within each outcome group.”49 Another critical Gross, F., B. Persaud, score, defined as a measure of the and C. Lyon (2010), likelihood of that site receiving a component of many case-control A Guide for studies is the matching of cases with Developing Quality specific treatment. Sites with and controls in order to control for the Crash Modification without the treatment are then Factors, Report effect of confounding factors. In FHWA-SA-10-032, matched based on their propensity cohort studies, sites are assigned to Federal Highway scores.”46 The matched data are Administration, a particular cohort based on current Washington, D.C. then used to estimate a cross treatment status and followed over Available at http:// sectional regression model. The www.cmfclearing time to observe exposure and event house.org/ propensity score method has been frequency. One cohort may include resources_ develop. cfm. Accessed July shown to reduce selection bias by the treatment and the other may be 2016. accounting for the non-random a control group without the 47 assignment of treatment sites. treatment. The time to a crash in Recently, the propensity score these groups is used to determine a 50 method is starting to be used in relative risk, which is the percentage See next page. place of traditional cross-sectional change in the probability of a crash methods to conduct evaluations.48 given the treatment.50

4-34 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS hazard locations are vulnerable to Before after studies 50 the RTM bias. This potential bias An analyst can use a before-after is greatest when sites are chosen Carter, D., R. study to evaluate a countermeasure Srinivasan, F. because of their extreme value (e.g., Gross, and F. by comparing the crashes before the high number of crashes or crash Council (2012), countermeasure was installed to the rate) in a given time period. A simple Recommended Protocols for crashes after installation. This study before-after evaluation has a high Developing Crash design is advantageous because likelihood of showing a much greater Modification the only change that has occurred Factors, Prepared benefit from the safety treatment as part of NCHRP at the site is the countermeasure than actually occurred. Project 20-07 (Task installation (assuming the analyst 314), Washington, As discussed earlier under the D.C. Available has researched the site histories at http://www. to discard any sites at which other network screening section, the EB cmfclearinghouse. significant changes occurred). method is one of the methods that org/resources_ has been found to be effective in develop.cfm. Accessed July 2016. There are issues for consideration dealing with the possible bias due to with this study design as well. RTM. The following steps are needed The analyst must know when the to conduct an EB before-after countermeasure was installed and evaluation: must have data, such as crash and 1. IDENTIFY a reference group of traffic volume, available in the before sites without the treatment, but and after periods. For high-cost, similar to the treatment sites high-profile countermeasures, such in terms of the major factors as road widening or traffic signal that affect crash risk including installation, the installation records traffic volume and other site will be readily available. However, for characteristics. One way to low-cost countermeasures, such as identify a reference group that sign installations, there may be little is similar to the treatment is to to no documentation on when they use the propensity score method were installed. discussed earlier under cross- The analyst might simply compare sectional studies. the number of crashes per year 2. Using data from the reference before the countermeasure to the site, ESTIMATE SPFs using data number of crashes per year after the from the reference sites relating countermeasure, known as a simple crashes to independent variables, or naïve before-after evaluation. such as traffic volume and other Although a simple before-after site characteristics. As discussed evaluation can be done easily in the following steps, SPFs using only crash data, it is prone to are used in the EB method to significant bias. One of the most predict the average number of influential biases for this method crashes based on AADT and site is the possible bias due to RTM. As characteristics. By selecting discussed earlier, RTM describes a the reference group to be situation in which crash rates are similar to the treatment group artificially high during the before in terms of the major risk period and would have been reduced factors, we can reduce the even without an improvement to possible bias due to confounding the site. Programs focused on high- on these predictions.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-35 Using an EB before-after evaluation to develop a CMF for signal phasing changes

This example is an illustration of an EB In this example: before-after evaluation that was conducted 51 51 as part of NCHRP Project 17-35. The 1 w = = 0.243 countermeasure was a change from ( 1 + 0.5641 × 5.535 ) Srinivasan, R. et permissive to protected-permissive left turn al., Evaluation of Safety Strategies phasing at signalized intersections in North at Signalized Carolina. Data from twelve locations were The EB estimate of the crashes in the before Intersections, period (EB ) = 5.535*0.243 + 10*(1-0.243) = NCHRP Report 705, used in this evaluation. A reference group b Washington, DC. of 49 signalized intersections was identified 8.917 crashes. for the development of SPFs. The analysis The predicted number of crashes from the looked at total intersection crashes, injury SPF in the after period was 11.391 (Pa). and fatal crashes, rear end crashes, and left The formula for the EB expected number turn opposing through (LTOT) crashes. In of crashes that would have occurred this example, only the data for LTOT crashes in the after period had there been no will be used. countermeasure is given by: The SPF for LTOT crashes based on the data π = EB × ( P / P ) from the reference group was: b a b

LTOT crashes/intersection/year = In this example, the EB expected number of crashes in the after period had the -0.3696 0.5564 e (MajAADT/10000) countermeasure not been implemented e0.6585×(MinAADT / 10000) (π) is equal to:

Where, MajAADT is the major road AADT 8.917 × ( 11.391 / 5.535 ) and the MinAADT is the minor road AADT. = 18.350 crashes The overdispersion parameter (k) for this SPF was 0.5641. The variance of this expected number of crashes is also estimated in this step: In the first site of this study, there were 10 observed crashes in the before period (X ), b Var( π ) = π × ( P / P ) × ( 1 - w ) and the predicted number of crashes from a b

the SPF in the before period was 5.535 (Pb). Where, Pa is the SPF predictions in the after The formula for obtaining the EB estimate period. In this example, the variance of ππ of the expected crashes in the before period is estimated as follows:

(EBb) is as follows: Var( π ) = 18.350 × ( 11.391 / 5.535 )

EBb = w × Pb + ( 1 - w ) × Xb × ( 1 - 0.243 ) = 28.603

This process was repeated for all 12 sites. Where, Xb is the observed crashes in the before period, and w is the EB weight that is Based on the data for all the 12 sites that calculated as follows: were used in the evaluation, the actual crashes in the after period were 115, the EB 1 expected crashes had the countermeasure w = not been implemented was 131.933 with a ( 1 + k × Pb ) variance of 140.080.

Where, k is the overdispersion parameter for the estimated SPF. (continued on next page)

4-36 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS The formula for the CMF and its standard CMF is the midpoint of a range of possible deviation (StDev) are as follows: values (i.e., the confidence interval). The standard deviation of the CMF can be estimated as follows: λsum π sum StDev( CMF ) = CMF = Var ( π ) 2 1 + sum 1 140.080 2 π2 0.865 ( + ) sum 115 131.9332

StDev( CMF ) = 140.080 ( 1 + ) 2 131.9332 Var ( λ ) Var ( π ) CMF2 sum + sum 2 2 = 0.111 λ sum π sum

Var ( π ) Based on this standard deviation sum 2 ( 1 + ) of the CMF, the approximate 95% 2 π sum confidence interval is (0.865-1.96×0.111, 0.865+1.96×0.111), which translates to a range of 0.647 to 1.083. Since this Where, λ is the total number of crashes sum confidence interval includes values greater that occurred in the after period, for all than 1.0, the CMF is not statistically the treated sites in the sample, π is the sum different from 1.0 at the 95% confidence total number of expected crashes in the level. This indicates that there is less after period had the countermeasure not confidence that this countermeasure been implemented, and Var represents the will reduce crashes compared to a variance. Since crashes are assumed to countermeasure whose CMF is significantly be Poisson distributed, Var(λ ) is usually sum different from 1.0. assumed to be equal to λsum. So, (Var(λsum))/ 2 (λsum ) will be equal to 1/λsum. In this example, the overall CMF was calculated as:

115 131.933 CMF = = 0.865 140.080 1 + 131.9332

This CMF of 0.865 indicates that the countermeasure (changing from permissive to protected-permissive left turn phasing) would decrease crashes, since the CMF is less than 1.0. It would be expected to decrease crashes by 13.5% (1.0 – 0.865 x 100 = 13.5). Again, it is important to recognize that the

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-37 3. In estimating SPFs, CALIBRATE The expected number of crashes 52 annual SPF multipliers to without the treatment along with Gross, F., B. account for the temporal effects the variance of this parameter and Persaud, and C. Lyon (2010), (e.g., variation in weather, the number of reported crashes after A Guide for demography, and crash the treatment is used to calculate Developing Quality the CMF and the standard deviation Crash Modification reporting) on safety. The annual Factors, Report SPF multiplier is the ratio of the of the CMF. This procedure is FHWA-SA-10-032, observed crashes to the predicted repeated for each treated site. Once Federal Highway Administration, crashes from the SPF. In using CMFs have been calculated for each Washington, the annual SPF multipliers from individual site in a group of treated D.C. Available sites, the CMFs can be combined to at http://www. the SPFs to account for temporal cmfclearinghouse. effects, it is assumed that the calculate the overall effectiveness org/resources_ of the countermeasure. More details develop.cfm. trends in the crash counts are Accessed July 2016. similar in the treatment and on this procedure are provided in reference groups. the previously mentioned guidance documents.52,53 53 4. USE the SPFs, annual SPF multipliers, and data on traffic In some cases, treatments may Carter, D., R. volumes for each year in the be installed system-wide for a Srinivasan, F. particular type of facility. For Gross, and F. before period for each treatment example, a jurisdiction may decide Council (2012), site to estimate the number of Recommended to increase the retroreflectivity crashes that would be predicted Protocols for of all their stop signs. Since sites Developing Crash for the before period in each site. Modification are not specifically selected based Factors, Prepared 5. CALCULATE the EB estimate on their crash history, the bias as part of NCHRP Project 20-07 (Task of the expected crashes in the due to RTM is minimal. However, 314), Washington, before period at each treatment it is still necessary to account for D.C. Available at http://www. site as the weighted sum of the changes in traffic volume and other cmfclearinghouse. actual crashes in the before trends. To evaluate the safety of org/resources_ such installations, an EB method develop.cfm. period and predicted crashes Accessed July 2016. from Step 4. could still be used, and while a reference group is not necessary, 6. For each treatment site, a comparison group is necessary 54 ESTIMATE the product of the EB in order to account for trends. estimate of the expected crashes SPFs can be estimated using the B. Persaud and in the before period and the SPF C. Lyon (2007), before-data from the treatment Empirical Bayes predictions for the after period sites and these SPFs can be used Before After divided by these predictions for to account for changes in traffic Studies: Lessons Learned from the before period. This is the EB volumes. In addition, SPFs could be Two Decades of expected number of crashes that estimated for a group of comparison Experience and Future Directions, would have occurred had there sites and the annual factors from Accident Analysis been no treatment. The variance these SPFs can be used to account and Prevention, of this expected number of for trends. Further details about 39(3):546-55. crashes is also estimated in such evaluations can be found this step. elsewhere.54

4-38 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS CHAPTER 12 UNIT 4: SOLVING SAFETY PROBLEMS System-Level Safety Management

System-level safety management involves addressing road safety System-wide vs. systemic? issues that affect the broad System-wide is a general term that refers transportation system, as opposed to treating safety issues across an entire to treating specific high priority transportation system using policies or campaigns. Systemic is a more specific sites. The size and scope of the term that refers to identifying a subset transportation system depends of a transportation system based on on the agency or jurisdiction. For risk factors and implementing safety a State DOT, the transportation efforts that address the particular characteristics of that subset. system would consist of all State- See page 4-41 for more discussion owned roads, signals, bridges, and on the systemic approach. other features across the entire State, whereas the transportation system for a town would consist of Identifying safety problems a much smaller area and roadway To identify safety problems on a network. Road safety at a system- system-level, safety professionals level often has to do with policies, analyze safety data that apply whether design policies for the to the entire jurisdiction. They construction and operation of roads examine crash data and link crashes and intersections, driver policies for to other safety data to determine licensing, or vehicle policies that the nature and locations of safety require certain safety technologies. problems. Problem identification on Other system-level efforts would a system-level involves identifying include broad media or enforcement crash trends and using risk-based campaigns. methods to prioritize safety efforts. Recall that Chapter 10 presented Identifying crash type trends road safety management in terms of three general components: Safety professionals can examine crash types and contributing factors JJ Identifying safety problems to determine the nature of crashes within their agency’s jurisdiction. JJ Developing potential This type of examination may reveal safety strategies crash trends, such as those related JJ Selecting and to alcohol involvement, seat belt implementing strategies use, driver age, or vulnerable road users. For example, crash data This chapter will discuss how each of might show that crashes involving these components can be addressed unbelted occupants have been at a system-level. increasing over the past several

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-39 years, or it might show that the number of crashes involving Florida’s emphasis on unbelted occupants is significantly motorcyclist safety higher than other nearby agencies, The State of Florida examined its crash such as adjacent counties or data to identify emphasis areas in the States. This would lead an agency development of their SHSP in 2012. One to consider how to increase seat area that continued to be a focus was motorcyclist safety. The data indicated belt use, perhaps through media that crashes involving motorcycles campaigns, increased enforcement, had decreased somewhat during the or educational campaigns in schools. time period analyzed (2006 to 1010) This type of agency-wide analysis but remained a significant portion of of crash data can demonstrate the crashes on Florida roads. Florida’s broad scale trends that need to safety professionals recognized that since Florida hosts numerous national be addressed through broad scale motorcycle events, the state’s SHSP efforts. should have motorcycle safety as an emphasis area. It is important that safety professionals are specific when 2,850 2,813 Serious Injuries identifying safety problems in 2,758 crash trends. For example, “crashes 2,548 involving teen drivers” is not 2,324 defined well enough, because the causes of crashes for 16 year-olds is markedly different from those of older, more experienced teens. Crashes in which teens are victims of other drivers’ errors require different solutions from those where the teen was at fault. Similarly, the Fatalities cause of crashes depends greatly on 550 550 532 402 383 the specific time, place and driving environment. A better target crash type would be “crashes occurring between 7-9 a.m. involving 16-year 2006 2007 2008 2009 2010 Strategic old drivers.” highway FIGURE 4-8. Florida motorcycle crash trend 2006-2010 safety plan Example of safety problem identification in A statewide- coordinated State Highway Safety Plans to as emphasis areas. The analysis safety plan can involve an examination of crash that provides a A good example of identifying proportions between categories of comprehensive safety problems from crash type framework trends can be seen in how States crashes, crash trends, crash severity for reducing develop strategic highway safety plans (e.g., fatal and serious injury), or highway (SHSPs). The development of a SHSP more advanced crash modeling fatalities and techniques. As presented in the serious injuries involves the identification of safety on all public problems on the State and local call-out boxes, Ohio and Florida roads. roads. A State analyzes safety data conducted analyses of their crash to determine the priorities, referred data and identified areas of concern.

4-40 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Ohio’s emphasis on older driver safety Ohio developed a SHSP in 2014 in which they identified fifteen emphasis areas. One of the emphasis areas was the safety of older drivers (65 and older). The crash data showed that older driver-related crashes accounted for 18% of highway deaths and 16% of serious injuries. They recognized that these numbers would likely increase with an aging population. The crash trends over the time period examined (2003 to 2013) showed a slight upward trend to older driver serious injuries and a slight downward trend to older driver fatalities. This contrasted to other types of crashes that experienced significant declines. These reasons motivated Ohio to make older driver safety an emphasis area in their 2014 SHSP.

Risk based prioritization – may indicate a higher-than-average the systemic approach risk for heart disease, even if the person has not yet experienced heart Chapter 11 presented various problems. Similarly, a section of methods of selecting high priority road with certain characteristics, sites through a process of network such as sharp curvature, old Systemic screening based on crash data. Many pavement, or lack of visibility, may safety professionals recognize that be at risk for run-off-road crashes, The process of identifying road this process of identifying specific even if none have occurred yet. or intersection locations using past crash data does Agencies can be proactive in their characteristics not adequately address the fact that approach to safety management that increase there may be locations that pose by identifying and treating these the risk of a safety threat but have not yet sites before crashes occur. These crashes and selecting experienced many (or any) crashes. treatments are often low cost, such locations This recognition led to an increased as signs and markings, so many for safety use of risk-based prioritization, also systemic-identified locations can be treatment called the systemic approach.55 treated within an agency’s limited based on the budget. presence of In this approach, a transportation these risk agency identifies priority locations An agency using the systemic factors. based on the presence of risk factors approach selects the focus crash rather than crashes. In the medical type(s) and identifies risk factors field, doctors pay attention to factors associated with the focus crashes. 55 that may elevate a person’s risk for Risk factors are site characteristics http://safety.fhwa. disease. A history of smoking, poor (e.g., design and operational dot.gov/systemic/ eating habits, and a lack of exercise features) that are common across

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-41 locations with the focus crash when selecting potential strategies type(s). The agency can identify risk as they may provide unique factors by analyzing crash data from perspectives. Safety professionals their jurisdiction or by reviewing should seek to involve local officials, previous research studies. Using citizens, and safety partners to the list of risk factors as a guide, the produce effective multidisciplinary agency identifies a list of sites with strategies. For example, addressing those specific characteristics, and a particular safety problem with then develops targeted treatments law enforcement and education to address or mitigate the specific can be far more economical than risk factors. The agency can apply implementing a multimillion- crash history and other thresholds dollar engineering fix. On the other to reduce the list of sites based on hand, law enforcement tends to available resources and program be effective only during the time objectives. in which it is active, so a more permanent engineering measure The systemic approach has two may be needed in some cases. It is attractive features. First, an agency often the case that a combination can employ the systemic approach of strategies is necessary to even for roads or intersections where effectively address the multitude of crash data are not fully available contributing factors. (e.g., where location accuracy is questionable or underreporting is On a system level, agencies must a problem). For instance, locating think broadly across the many crashes accurately and precisely in disciplines represented by those rural areas or on non-State owned who have a stake in road safety. urban roads can be difficult. Second, Potential strategies might address the systemic approach is useful infrastructure policies and practices for treating safety issues where (e.g., design standards, speed limits, crashes are highly dispersed, such etc.) or they may be directed at as on rural or low volume roads. specific population focused efforts Specifically, agencies can use the (e.g., seat belt laws, helmet laws, systemic approach to address young driver restrictions, etc.). existing and potential safety issues across a large portion of the network Just as the identification of problems (e.g., shoulder rumble strips on all was based on safety data, so too rural, two-lane roads with a certain must the development and selection shoulder width and traffic volume of strategies be driven by the data. level). If an agency identified concerning trends in certain types of crashes, Developing potential then they should further examine safety strategies the crash data to determine how best to address the safety problem. After safety professionals analyze For example, Figure 4-9 shows an data and identify safety problems, example of alcohol-related crashes they must develop potential where an agency identified a spike in strategies to address the problems. frequency (or high pole) of crashes It is important to engage safety occurring near 2:00 AM. Further stakeholders and other partners examination revealed that bars in

4-42 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Case Study: Systemic Analysis in Thurston County, Washington

The Thurston County Public Works JJ Speed differential between posted Department in Washington conducted approach speed and curve advisory a systemic safety analysis for their road speed of 0, 5, and 10 miles per hour network. Based on a review of severe crashes, Thurston County decided to focus JJ Presence of a visual trap (a minor road on roadway departure crashes in horizontal on the tangent extended) curves on arterial and collector roadways Thurston County decided that a risk factor when it found that: could be worth one point or a one-half 1. Most of the severe crashes occurred point. Those factors present in at least 30% due to roadway departures, and that of the severe (fatal and injury) crashes and overrepresented by at least 10% (when 2. 81% of the severe curve /roadway comparing the proportion of all locations departure crashes occurred on arterial with the proportion of severe crash and collector roads. Because this effort coincided with ongoing efforts locations) were used as a guideline to have to identify and upgrade warning a high confidence and assigned one point signs for horizontal curves on their in the risk assessment process. The risk County road system, Thurston County factors that had a lower confidence in their chose to focus on currently signed relative data were assigned one-half point. horizontal curves. Thurston County then tallied the number Thurston County accessed an inventory of risk factors present for each of the of their roads and intersections through curves. The risk factor totals for the ten a database maintained by the Statewide curves with the highest scores ranged County Road Advisory Board. In addition, from 4.5 to 6.0. All 270 signed curves Thurston County assembled crash data were prioritized for potential low cost for the 2006-to-2010 timeframe from the safety investments. They identified the Washington State DOT crash database. following low-cost, low-maintenance They linked the road, intersection, and countermeasures with documented curve data with crash data and used these crash reductions to implement at the data to identify risk factors. Thurston selected locations: County assembled a list of 19 potential risk factors and then performed a descriptive JJ Traffic signs – enhanced curve statistics analysis to identify 9 risk factors delineation with the addition of for use in screening and prioritizing chevrons and larger advance candidate locations. The identified risk warning signs factors were: JJ Pavement markings – dotted extension JJ Roadway class of major rural collector lines at intersections and recessed JJ Presence of an intersection raised pavement markers

JJ Traffic volume of 3,000 to 7,500 JJ Shoulder rumble strips 56 annual average daily traffic JJ Roadside improvements – object J removal, guardrail, and slope flattening “Thurston County, J Edge clearance rating of 3 Washington, Public Works Department JJ Paved shoulders equal to or Systemic analysis provided Thurston Applies Systemic greater than 4 feet in width County a proactive, data-driven, and Safety Project defensible approach to identifying curves Selection Tool” JJ Presence of a vertical curve FHWA-SA-13-026, for improvement prior to a severe crash June 2013. http:// JJ Consecutive horizontal curves occurring, rather than reacting after an safety.fhwa.dot.gov/ (windy roads) incident has occurred.56 systemic/

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-43 20 Example of a high pole in a jurisdiction where bars close at 2:00 a.m. 15

10

5 NUMBER OF COLLISIONS 0 0:00 2:00 4:00 6:00 8:00 10:00 12:00 14:00 16:00 18:00 20:00 22:00 TIME OF DAY

FIGURE 4-9. Example of “high pole” in crash data (Source: NCHRP Report 501)

that jurisdiction closed at 2:00 AM. This could lead to potential strategies, Consider How Specific Behaviors such as increased enforcement of Influence the Safety Problem impaired driving at that time of night Safety professionals must identify and in the vicinity of bars. and target road user behaviors that contribute to the identified safety It is also important to use the data problem. The target behavior should to determine the necessary scope of be specific. For example, “safe driving” the intervention. If the data show is not a specific behavior that can be that the problem exists year-round, changed because it involves a number of different behaviors. However, “speeding then the solution needs to match on Main Street” is a specific behavior that. For example, a “safe ride that can be targeted. It is also important program” for drinkers to get home to consider the factors influencing this on New Year’s Eve is not going to behavior. Why are people speeding on significantly impact the problem of Main Street? Which social, cultural, or environmental factors are influencing impaired driving overall. this behavior? Does it vary by time of day Critical thinking is needed to or week, perhaps reflecting the kind of drivers who are speeding? develop effective solutions to the safety problems at hand. Analysts should look for characteristics of 1. ASK the questions, “Is this crash trends that could be addressed information sufficient for action 57 by practical strategies. An NCHRP item development? If not, what Bahar, G., M. report on an integrated safety further information is needed to Masliah, C. Mollett, management process states that and B. Persaud, act on this finding?” Integrated Safety safety professionals should use Management safety data to perform “further 2. CONSIDER cross tabulations of Process, National analyses of those characteristics Cooperative two variables within the subset Highway Research that are found to be significantly of data that pertains to the Program, Report or practically over-represented on activities under consideration 501, Transportation 57 Research Board a percentage or rate basis.” The if one or more of the following of the National report gives a set of guidelines to be types of conditions hold: Academies, considered in analyzing crash data to Washington, D.C., 2003 identify trends and develop potential JJ If the activities are time safety strategies: critical (e.g., all selective

4-44 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS enforcement strategies), 17- to 20-year-old causal perform a time-of-day by driver crashes. As another day-of-the-week analysis. example, insight into youth As an example, alcohol- alcohol enforcement activities related crashes will likely be can be attained by comparing over-represented in the early alcohol-related crashes of 16- morning and on weekend to 20-year-old causal drivers days. A logical approach is to against alcohol-related crashes perform a cross tabulation of of their 21-year-old and older time-of day by day-of-the- counterparts. Each of these week to determine the best types of comparisons can times and days for driving show differences between the under the influence (DUI) respective subpopulations. selective enforcement. The goal of the procedure at 4. USE the results of each analysis this point is to determine to determine what further additional details (who, what, information is needed before where, when, and how) for the best decision can be made, those crash types identified and repeat the analysis with the 58 by the analyses performed to additional information. Bahar, G., M. this point. 5. PERSIST and maintain a thread Masliah, C. Mollett, and B. Persaud, JJ If the over-represented of evidence until the information Integrated Safety variable is not constant available has been exhausted. Management Process, National over all crash severities, If the information generated Cooperative cross tabulate the variable indicates a significant factor, Highway Research create further subsets of the data Program, Report by severity (e.g., nighttime, 501, Transportation rural, and older-driver (e.g., youth-pedestrian crashes), Research Board crashes tend to be more and repeat the entire analysis. of the National Academies, severe). 6. REJECT any strategies and Washington, D.C., 2003 JJ If the activities can be activities at this point that targeted to geographic the data clearly show to be counterproductive (i.e., activities location, age group, 59 gender, race, or any other that will consume resources demographic factor within that could be better applied Goodwin, A., Thomas, L., the crash records, consider elsewhere). Maintain a list of Kirley, B., Hall, W., these variables for cross all potential strategies and O’Brien, N., & Hill, corresponding activities that will K. Countermeasures tabulation with other over- That Work: A represented variables. be subjected to further analysis Highway Safety in the optimization procedure.58 Countermeasure 3. CONSIDER creating subsets Guide for State Highway Safety of the data for additional Many system-level safety strategies Offices, Eighth comparisons where activities focus on behaviors of drivers edition, National are to be targeted to a particular and other road users. Resources Highway Traffic Safety subgroup of the population. For like Countermeasures That Work Administration, example, insight into a graduated provide a useful listing of potential Report No. DOT HS 812 202, driver’s license strategy can be safety strategies for system-level Washington, DC, obtained by comparing 16-year- safety management.59 The excerpt 2015. old causal driver crashes against from Countermeasures That Work in

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-45 FIGURE 4-10. Potential Safety Strategies to Address Speeding and Aggressive Driving

1. Laws

COUNTERMEASURE EFFECTIVENESS COST USE TIME † 1.1 Speed limits  $ High Short

1.2 Aggressive driving laws  $ Low Short

† When enforced and obeyed

2. Enforcement

COUNTERMEASURE EFFECTIVENESS COST USE TIME

2.1 Automated enforcement  $$$† Medium Medium

2.2 High-visibility enforcement  $$$ Low†† Medium

2.3 Other enforcement methods  Varies Unknown Varies

† Can be covered by income from citations †† For aggressive driving, but use of short-term, high-visibility enforcement campaigns for speeding is more widespread

3. Penalties and Adjudication

COUNTERMEASURE EFFECTIVENESS COST USE TIME

3.1 Penalty types and levels  Varies High Low

3.2 Diversion and plea agreements  Varies Unknown Varies

4. Communications and Outreach

COUNTERMEASURE EFFECTIVENESS COST USE TIME

4.1 Public Information Varies Medium Medium supporting enforcement 

Effectiveness:  Demonstrated to be effective by several high-quality evaluations with consistent results  Demonstrated to be effective in certain situations  Likely to be effective based on balance of evidence from high-quality evaluations or other sources  Effectiveness still undetermined; different methods of implementing this countermeasure produce different results  Limited or no high-quality evaluation evidence

4-46 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Figure 4-10 gives a list of potential strategies for addressing speeding- Florida’s strategies for related crashes, from either motorcyclist safety laws, enforcement, penalties and After identifying motorcyclist safety as adjudication, or communications an emphasis area in their 2012 SHSP, and outreach. The list also includes Florida identified a list of strategies to an indication of the effectiveness, address motorcyclist safety. Example strategies include: cost, current usage, and time of each strategy, which are all important JJ Promote personal protective considerations when selecting safety gear and its value in reducing strategies to implement. motorcyclist injury levels and increasing rider conspicuity If the agency identifies safety JJ Promote adequate rider training problems from a systemic analysis, and preparation to new and the potential safety strategies experienced motorcycle riders should address the types of crashes by qualified instructors at State- that were related to the roadway approved training centers characteristic risk factors. These JJ Incorporate motorcycle-friendly strategies may often be engineering policies and practices into roadway improvements related to the design, traffic control, construction, risk factors. For example, if an operation, and maintenance examination of crash trends may JJ Develop and implement highlight run-off-road crashes, communications strategies that and a systemic analysis would target high-risk populations and identify the type(s) of road on which improve public awareness of run-off-road crashes are likely to motorcycle crash problems and programs. occur. Table 4-12 shows a list of potential safety strategies that could be implemented for engineering respectively. The SHSPs from these treatments for a run-off-road crash problem. In a systemic approach, States also demonstrated the types these engineering treatments would of safety strategies each State be implemented across some or all intended to pursue to combat the roads meeting the risk factors that safety problems in these areas. increase the likelihood of run-off- road crashes. Selecting and implementing strategies Example of system-level safety strategies in A transportation agency must determine which of the potential state highway safety plans strategies they will implement SHSPs provide many good examples to address the identified safety of system-level strategies that problems. Since system-level safety address safety problems identified solutions can involve broad changes through analysis of crash and other to policies, design practices, or safety data. The previous section jurisdiction-wide road user behavior, showed how Ohio and Florida there are different issues to consider had identified safety priorities on compared to implementing a older drivers and motorcyclists, safety countermeasure at a specific

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-47 RELATIVE COST TO IMPLEMENT EFFECTIVE- OBJECTIVES COUNTERMEASURES AND OPERATE NESS

15.1 A: KEEP 15.1A1: Install shoulder Low Tried VEHICLES rumble strips FROM ENCROACHING ON THE ROADSIDE 15.1 A2: Install edgelines “profile marking”, edgeline rumble strips or modified Low Experimental shoulder rumble strips on section with narrow or no paved shoulders

15.1 A5: Provide improved highway geometry for High Proven horizontal curves

15.1 A6: Provide enhanced Low Tried pavement markings

15.1 A7: Provide skid- Moderate Proven resistance pavement surfaces

15.1 B: 15.1 B1: Design safer slopes MINIMIZE THE and ditches to prevent Moderate Proven LIKELIHOOD OF CRASHING rollovers INTO AN OBJECT OR OVERTURNING IF THE VEHICLE 15.1 B2: Remove/relocate Moderate TRAVELS OFF Proven THE SHOULDER objects in hazardous locations to High

15.1 C: REDUCE 15.1 C1: Improve design of Moderate Tried THE SEVERITY roadside hardware to High OF THE CRASH

15.1 C2: Improve design and Moderate application of barrier and Tried to High attenuation systems

TABLE 4-12. Potential Safety Strategies for Run-Off-Road Crashes (Source: NCHRP 500, Volume 6)

4-48 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS location. Many more people will be affected by the system-level Ohio’s strategies for changes. This carries great promise older driver safety in that safety might be improved Ohio identified three strategies to across an entire system, but it also address the older driver emphasis area carries unique challenges. in their 2014 SHSP: JJ Coordinate older driver messages Agencies will need to consider the developed by multi-agency following questions when selecting communication committee. strategies to implement: JJ Create a comprehensive and JJ Safety effectiveness – How coordinated outreach effort that likely will it address the safety educates older drivers and their caregivers on driving risks and problem? remedies. JJ Public acceptance – How will JJ Encourage roadway design and the strategy be accepted by the engineering measures that reduce public? What kind of marketing the risks of traffic crashes for older drivers. will be needed to communicate the intent and benefit of the strategy? outreach for agencies who seek to JJ Stakeholders and partners – implement system-level safety Which parties will need to be strategies. involved in implementing the Evaluating a system-level strategy strategy? (e.g., program or intervention) to JJ Cost efficiency – What kind of determine its effectiveness is a return on the dollar would be critical but often overlooked step. expected? The transportation agency in charge JJ Time – How long will it take to should evaluate the effect of the implement the strategy? safety strategy using good quality data; ideally the same type of data Communication is critically that was used to identify the safety important for system-level safety problem initially. If a program or strategies. Both the general public intervention is not effective, the and road users affected by the overseeing agency should consider strategy must understand the why this might be the case. Can the benefits. Other public agencies program be improved, or should may need to integrate their efforts other approaches be considered with the proposed safety strategy. Administrators, lawmakers, instead? If successful, how can the and other key decision-making intervention be institutionalized personnel must understand how to ensure long term support (and the strategy will improve road therefore lasting change)? Finally, safety for their constituency and it is important to remember that bring an overall financial benefit. success or failure in one location Unit 5 provides more discussion on does not guarantee the same results communication, marketing, and at a different location.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-49 Example of System-Level unsafe driving. Teens are crashing Safety Management largely because they lack the driving experience that equips most drivers The following provides an to intuitively/near instantaneously example of using system-level do the things necessary to avoid safety management to address a crashing. Because of this, changing specific problem. This example the environment is more likely demonstrates the three general to be effective. components of safety management presented in this unit. The officials recognize that eliminating the policy that allows 1. Identify the safety problem. students to leave campus during County A noticed a large number lunch would lead to a reduction in of crashes involving 16-17 year old crashes during this time. This policy drivers occurring weekdays between would eliminate exposure to the 11:00am and 1:00pm. Neighboring risky driving situation and reduce counties have not experienced this the potential for crashes. problem. County officials coordinate with school district staff to tackle 3. Select and implement strategies. this issue. The school districts accordingly In exploring the problem, the eliminate the policy allowing officials discover that County A is students to leave campus during the only jurisdiction that has an lunch. They recognize that this open campus lunch policy allowing policy change should be evaluated students to leave school during to determine its safety effect. Crash their lunch period. Allowing teens data would be needed to examine 60 to leave campus during lunch whether the closed school lunch means there are many young, Tefft B.C., Williams policy has an effect on weekday A.F., & Grabowski inexperienced drivers on the roads at crashes between 11:00am and J.G. (2013). Teen the same time. They may be carrying driver risk in relation 1:00pm. However, it will take many additional passengers which to age and number years to accumulate enough data of passengers, research has established leads to for this evaluation. In this example, United States, an increased risk of a fatal crash.60,61 2007-2010. Traffic there is a proxy measure that can Injury Prevention, The brief lunch period also results in be used in the interim. A before and 14, 283-292. pressure to get back in time for the after observational survey with an next class. Combined, these factors lead to a risky driving situation and appropriate control could quantify 61 an increased risk of crashing. the number of students leaving campus during lunch before and Chen, L., Baker, S.P., Braver, E.R., & Li, 2. Develop potential safety strategies. after the change. In this case the G. (2000). Carrying officials know that the proxy measure Passengers as a Risk In this situation, an informational Factor for Crashes approach that simply tells teenagers (reduced driving from 11:00am to 1:00 Fatal to 16- and pm) is a guaranteed indicator of crash 17-Year-Old Drivers. about the problem would likely Journal of the not make a difference. Teens are reduction for this specific problem. American Medical However, it is not often the case that Association, 283, not crashing because they lack 1578-1582. information about the importance of proxy measures are so closely aligned safe driving or the consequences of to the outcome of interest.

4-50 UNIT 4: SOLVING SAFETY PROBLEMS ROAD SAFETY FUNDAMENTALS Unit Summary conducting an economic appraisal for all options, prioritizing the Solving road safety problems countermeasure projects based on requires a comprehensive process estimated costs and benefits, and to identify safety problems, evaluating the countermeasure develop potential safety strategies, performance afterwards. Safety and select and implement those management at a system-level strategies. To get the most effective involves identifying safety problems results, this process must be based by examining crash trends or using on solid safety data, particularly a systemic approach to identifying good quality crash data. The high-risk road characteristics. methods of undertaking the safety State agencies who are developing management process will depend on system-wide safety strategies the scope of the effort. must examine the data trends Safety management of individual and the road users involved. They sites involves a six-step process of must consider factors, such as how screening the network for high- system-wide policies and programs priority sites, diagnosing the safety will be accepted by the public and issues at those sites, selecting who will be the partners to involve appropriate countermeasures, in implementing the safety strategy.

ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-51 EXERCISES

JJ PRESENT an example road safety 11 on site-level safety management to problem and compare and contrast the this location (the network screening ways in which the problem could be step would not apply since this location addressed at a system-level vs. site-level. is already identified). Consider safety strategies across a range of disciplines JJ Your state has a small, rural, (e.g., engineering, law enforcement, mountainous county where a large public communication and education, number of motorcycle crashes are etc.). happening. The crash rate per registered motorcycle in this county is nearly 10 JJ This exercise should be conducting times the state average. Upon further using the Excel spreadsheet that investigation you learn that this county accompanies this book. The goal of this is a popular motorcycling tourist exercise is to USE selected performance destination. People come from all over metrics to create a ranked list of sites the country to ride the curvy mountain for further investigation as part of a roads. In fact, the majority of people network screening effort. The Excel involved in crashes are not from that spreadsheet includes nearly 1,400 area at all. Clusters of crashes occur intersections, or sites. Each site has a on certain curves. What are some unique ID number, traffic volume data, approaches that could be used to reduce and other information about its location crashes in this county? How could these and characteristics. Three performance approaches be evaluated? In particular, metrics have been calculated for each DETAIL how you would apply the three site. These have been calculated using major components described in this five years of data (2010-2014) and one unit: year of data (2014), resulting in a total of six performance metrics per site. Your JJ Identify the safety problem assignment is to rank the sites using JJ Develop potential safety strategies these various performance metrics and document the results. Document the JJ Selecting and implement strategies twenty highest priority sites based on When you work through this process, each method. Use the results to answer recall the discussion of human behavior the following questions: from Unit 2. What are possible behaviors JJ What were some of the sites leading to the safety problem? What that routinely ranked in the top other factors could be influencing this twenty? What were some of their behavior? How does this affect your characteristics (volumes, number of identification and selection of potential lanes, stop/signal control)? safety strategies? JJ Were there any sites that were JJ If possible, OBTAIN three to five years of only occasionally present in the crash data for an intersection or section top twenty? What were some of road in your area. You will likely need characteristics of these sites? to contact the controlling agency – the State DOT, county, or city. Describe how you would apply the steps in Chapter

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ROAD SAFETY FUNDAMENTALS UNIT 4: SOLVING SAFETY PROBLEMS 4-53 UNIT 5 Implementing Road Safety Efforts LEARNING OBJECTIVES

After reading the chapters and completing JJ DEFINE three areas of exercises in Unit 5, the reader will be able to: road safety research

JJ IDENTIFY the current road safety JJ DEFINE the characteristics of partner agencies and define their role strategic communications in addressing safety problems JJ RECOGNIZE potential avenues for advancing road safety efforts

5-b UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS CHAPTER 13 IMPLEMENTING ROAD SAFETY EFFORTS Who Does What

The greatest gains in road safety international scale – the United occur when transportation agencies Nations (U.N.) used a generalization work together rather than tackling called the “Five Pillar” structure as problems alone. This can be part of the Decade of Action for Road challenging given the fragmented Safety. 1 The U.N. recognized that 1 nature of transportation governance efforts to improve road safety must in the U.S. There are numerous address various pillars including United Nations, agencies operating in different focus road safety A/RES/64/255, Geneva, 2010 areas and at different levels. This management, safer roads and mobility, chapter presents an overview of the safer vehicles, safer road users, and various agencies and organizations better post-crash response. 2 that have a direct hand in advancing 2 Likewise, U.S. transportation road safety and the initiatives that Global Status agencies are organized to address they undertake. Report on Road focus areas that are similar in theme Safety 2013: U.S. transportation agencies are to the U.N. five pillars, though not Supporting a Decade of Action, typically structured around particular the same. Table 5-1 shows how World Health focus areas, such as roadway, agencies at all levels (Federal, State, Organization, ISBN 978 92 4 156456 4, vehicles, or road users. This and local) address five focus areas in 2013. approach is also seen on the road safety.

FOCUS AREA FEDERAL STATE LOCAL

City public works Road Design / Federal Highway Departments of Environment Administration transportation Metropolitan/rural planning organizations

Highway safety offices Road User National Highway Departments of No specific agency Behavior Traffic Safety motor vehicles Administration Health departments Federal Motor Carrier Safety Vehicle Design / Departments of Administration No specific agency Technology motor vehicles

State police / Law Enforcement No specific agency Police departments highway patrol

Metropolitan planning Federal Transit Transit Safety No specific agency organizations Administration Municipal transit agencies

TABLE 5-1: Transportation Agencies by Focus Area

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-1 Federal Agencies In addition, FHWA oversees the Local and Tribal Technical The Federal role in implementing Assistance Program (LTAP/TTAP), road safety initiative is carried out which provides information and largely through the U.S. Department training programs to local agencies of Transportation (USDOT) and the and Native American Indian tribes many agencies under that department. to improve road safety.3 Further, 3 These agencies are each tasked with FHWA maintains division offices in a specific focus area as the Federal each state to deliver assistance to “About the National Government seeks to address safety Program,” last partners and customers in highway updated June 20, issues for various modes of travel. transportation and safety services at 2013, accessed June These agencies include: 20, 2013, http:// the State level. www.ltap.org/about/. JJ Federal Highway Administration National Highway Traffic JJ National Highway Traffic Safety Administration Safety Administration

JJ Federal Motor Carrier Safety www.nhtsa.gov Administration Focus Areas: Road User Behavior JJ Federal Transit Administration and Vehicle Design and Technology

JJ Federal Railroad Administration The National Highway Traffic Safety Administration (NHTSA) Federal Highway focuses on the safety of the vehicle, Administration driver, and road user. NHTSA investigates safety defects in motor www.fhwa.dot.gov vehicles, establishes and enforces Focus Area: Road Design safety performance standards for and Environment motor vehicles and motor vehicle equipment, sets and enforces fuel The Federal Highway Administration economy standards, collects data, (FHWA) works to reduce highway and conducts research on driver fatalities through partnerships with behavior and traffic safety, and State and local agencies, community helps states and local communities groups, and private industry. The reduce the threat of impaired FHWA Office of Safety advocates driving and other dangerous designs and technologies that improve road user behaviors. road safety and administers safety programs, such as the Highway NHTSA carries out research and Safety Improvement Program (HSIP). demonstration programs in many 4 FHWA’s Resource Center also provides behavioral areas including impaired driving, occupant protection, speed “Who We Are and technical assistance, technology What We Do,” deployment, and training. FHWA has management (shared with FHWA), accessed June 20, a significant role in safety research pedestrian, motorcycle and bicycle 2013, https://www. nhtsa.gov/about- through the Office of Safety Research safety, older and younger road users, nhtsa. and Development, which develops drowsy, and distracted driving. and implements safety innovations NHTSA is also the lead Federal through teams of research engineers, agency for emergency medical scientists, and psychologists. services (EMS) and 9-1-1 systems.

5-2 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS Federal Motor Carrier monitors, and ensures Safety Administration compliance with the commercial driving licensing standards for www.fmcsa.dot.gov drivers, carriers, and States.

Focus Areas: Road User Behavior JJ Motor Carrier Safety Identification and Vehicle Design and Technology and Information Systems: FMCSA provides safety data, State The Federal Motor Carrier Safety and national crash statistics, Administration (FMCSA) focuses current analysis results, and on reducing crashes, injuries, and detailed motor carrier safety fatalities involving commercial use performance data to industry of large trucks and buses. FMCSA and the public. This data allows develops and enforces research- Federal and State enforcement based regulations that balance officials to target inspections safety and efficiency. The agency and investigations on higher risk manages safety information systems carriers, vehicles, and drivers. to enforce safety regulations with regards to drivers who have high JJ Safety education and outreach: risk in factors, such as health, age, FMCSA implements educational experience, and education. strategies to increase motor carrier compliance with the FMCSA also targets educational safety regulations and reduce messages to carriers, commercial the likelihood of a commercial drivers, and the public.5 Some key vehicle crash. Messages are programs administered by the 5 aimed at all highway users agency include: including passenger car drivers, “About FMCSA,” accessed June 20, JJ Commercial Driver’s License truck drivers, pedestrians, 2013, https://www. Program: FMCSA develops, and bicyclists.6 fmcsa.dot.gov/ mission/about-us.

6

“Key FMCSA Programs,” accessed October 15, 2013, https:// www.fmcsa.dot.gov/ mission/we-are- fmcsa-brochure.

The Federal Motor Carrier Safety Administration develops, monitors, and ensures compliance with commercial driving licensing standards.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-3 The Federal Transit Administration seeks to improve public transportation, such as buses.

Federal Transit Administration for protecting, repairing, and/ or replacing equipment and www.transit.dot.gov facilities that may suffer or have Focus Area: Transit Safety suffered serious damage because 7 of an emergency including The Federal Transit Administration natural disasters. “Federal Transit (FTA) seeks to improve public Administration,” transportation by assisting State and JJ Research, Development, last updated September 6, local governments with planning, Demonstration, and Deployment 2013, https:// implementation, and financing of Projects: This program supports www.usa.gov/ public transportation projects.7 FTA federal-agencies/ research activities that improve federal-transit- manages many transit-oriented the safety, reliability, efficiency, administration. safety programs including: and sustainability of public JJ Bus and Bus Facilities: This transportation. 8 program provides capital funding JJ Transit Safety and Oversight: FTA to replace, rehabilitate, and “MAP-21 Programs,” has the authority to establish and purchase buses and related accessed October enforce a new comprehensive 16, 2013, https:// equipment and to construct bus- framework to oversee the www.transit.dot. related facilities. gov/regulations- safety of public transportation and-guidance/ JJ throughout the United States legislation/map-21/ Public Transportation Emergency map-21-program- Relief Program: This program as it pertains to heavy rail, fact-sheets. helps States and public light rail, buses, ferries, and transportation systems pay streetcars.8

5-4 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS Federal Safety Programs for improving highway safety through the implementation of Federal agencies advance road such infrastructure improvements.9 9 safety through numerous programs States are also required to report to and initiatives. Federal programs the U.S. Secretary of Transportation Source: “Highway can be very influential due to large on progress made implementing Safety Improvement funding sources provided by Federal Program (HSIP),” highway safety improvements and accessed August 12, legislation. These funds are often the extent to which fatalities and 2013, http://safety. distributed to State and local levels fhwa.dot.gov/hsip/ serious injuries on all public roads and “HSIP History,” to implement various improvements have been reduced. accessed August to roads and intersections. 12, 2013, http:// safety.fhwa.dot. Specific funding programs can Traffic Records Improvement gov/hsip/gen_info/ hsip_history.cfm. change with each new piece of Grants (NHTSA) transportation legislation. However, NHTSA administers Federal funding it may be useful to look at an to encourage States to implement overview of some of the types of programs that will improve the current and past funding programs. timeliness, accuracy, completeness, Below are listed a few programs uniformity, integration, and that have been widely used through accessibility of State data used in the years to develop and implement traffic safety programs. The Federal improvements to road safety: 10 SAFETEA-LU legislation established JJ Highway Safety Improvement this program of incentive grants, NHTSA, Section 408 SAFETEA-LU Program (FHWA) and the funding continued under Fact Sheet, subsequent legislation. The funds https://one. JJ Traffic Records Improvement nhtsa.gov/Laws- were to be used to evaluate the Grants (NHTSA) &-Regulations/ effectiveness of efforts to make Section-408- SAFETEA% JJ Safety Data Improvement Program safety data improvements, to link E2%80%93 Grant (FMCSA) safety data systems within the State, LU-Fact-Sheet and to improve the compatibility Highway Safety Improvement of the State data system with national data systems and data Program (FHWA) Data-driven systems of other States. A State HSIP is a Federal program focused may use these grant funds only to An approach on infrastructure improvements that implement such data improvement of which the priorities are will lead to significant reduction in programs. To qualify, a State must traffic fatalities and serious injuries determined by meet certain requirements including examination of on all public roads. HSIP is Federally a functioning Traffic Records crash data or funded and administered by FHWA, Coordinating Committee (TRCC), other objective but it is implemented by the State a strategic plan to address data and reliable departments of transportation deficiencies, and a regular traffic safety data, rather than per the strategies laid out in the records assessment.10 State’s Strategic Highway Safety priorities set by preferences of Plan (SHSP). Funding is provided Safety Data Improvement a few parties, for safety-related infrastructure Program Grant (FMCSA) current “hot” improvements, such as sidewalks, topics, or high traffic calming, or signing upgrades. The Safety Data Improvement profile rare The States are required to develop Program (SaDIP), administered events. a data-driven, strategic approach by FMCSA, provides financial and

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-5 technical assistance to States to State Agencies improve data collected on truck and bus crashes that result in All fifty States, the District of Columbia, and Puerto Rico injuries or fatalities. The assistance administer road safety programs. is provided to State departments State agencies administer roadway of public safety, departments systems, driver licensing, injury of transportation, or State law prevention programs, traffic law enforcement agencies. SaDIP funds enforcement, and other road safety have been used to hire staff to code activities. However, assignment of safety performance data, purchase these responsibilities varies widely software for field data collection, from State to State. In many cases, and revise outdated crash forms. two or three government agencies FMCSA maintains the Motor Carrier are responsible for most or all Management Information System of these activities. Other States (MCMIS) and supplies access to the distribute these responsibilities system for designated employees in to numerous agencies and each State through SAFETYNET, an offices. Regardless of how these online network of safety data. States responsibilities are distributed, use MCMIS and SAFETYNET to enter States share a vital role in improving data on motor carriers, drivers, road safety for all citizens. compliance reviews, inspections, In general, State agencies that and crashes. At the national level, address road safety issues include: FMCSA uses the data to characterize the safety experience of commercial JJ State departments motor vehicles, and to help States of transportation with the task of identifying high JJ State highway safety offices risk carriers and drivers. The data are also used by motor carrier JJ State departments companies, safety researchers, of motor vehicles advocacy groups, insurance JJ State highway patrols companies, the public, and a variety of other entities. JJ State health departments

State departments of transportation oversee design, construction, maintenance, and operation of roads.

5-6 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS State Departments also develops long-range (20 to of Transportation 30 year) transportation plans and short range (five to 10 year) Focus Area: Road Design plans that outline the vision of the and Environment transportation network and which projects will be constructed to fulfill Each State has a department of that vision. transportation (DOT), which oversees the design, construction, State Highway Safety Offices maintenance, and operation of the State’s roads. This agency may Focus Area: Road User Behavior also be called the State Highway State Highway Safety Offices Administration or Department (SHSOs) administer a variety of of Roads. State DOTs have many national highway safety grant official responsibilities. For highway 11 safety issues, State DOTs have programs authorized and funded 11 official transportation planning, through Federal legislation. The “SHSO Programs & governor of each State appoints a Funding,” accessed programming, and project June 20, 2013, implementation responsibility. highway safety representative to http://www.ghsa. administer the Federal Highway org/about/federal- These agencies typically oversee grant-programs. all Interstate highways and most Safety Grant Program and numerous primary highways (State highways). other highway safety programs State DOTs focus on roadway designated by Congress. The safety, and thus work in direct governor’s representative promotes partnership with FHWA. They serve safety initiatives in the State, such as liaisons between the Federal and as high visibility enforcement local transportation agencies and campaigns like Click It or Ticket. provide resources and technical The State Highway Safety Office assistance to local agencies. State focuses on behavioral aspects of DOTs coordinate the use of Federal roadway users, and thus works in HSIP funds to improve roads and direct partnership with NHTSA. intersections on the local level. Safety programs implemented by In some States, the DOT the SHSO include: administers, maintains, and JJ Encouraging safety belt, child car operates county and city streets or seat, and helmet use secondary roads. State DOTs also work cooperatively with tolling JJ Discouraging impaired driving authorities, ports, local agencies, JJ Promoting motorcycle safety and special districts that own, operate, or maintain portions of the JJ Improving the skills of younger transportation network. and older drivers The State DOT typically leads State Departments the development of the SHSP, a statewide-coordinated safety plan of Motor Vehicles that provides a comprehensive Focus Area: Vehicle Design framework for reducing highway and Technology fatalities and serious injuries on all public roads. The State DOT State Departments of Motor Vehicles

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-7 State highway patrols enforce motor vehicle laws Coordinated and regulations, investigate People from crashes, and many agencies work to identify come together enforcement to develop an needs. SHSP, including those from the department of transportation, (DMVs) administer State programs investigate motor vehicle crashes, department for driver licensing, and automobile which are important sources of of motor inspection and registration. State and Federal crash data. They vehicles, state highway patrol, Generally, DMVs reside either within work closely with State highway public health, the State DOT or a department of safety representatives to identify universities, public safety. A few States have a enforcement needs. They play a and others. cabinet-level DMV. vital role in implementing impaired driving laws, safety belt use, and The DMV is responsible for other safety programs. Certain identifying at-risk drivers and troopers in the State highway Comprehensive maintaining driver records. The agency also implements driver patrol are tasked with inspecting Using all types license standards, monitors large trucks to ensure the driver of strategies to and the vehicle comply with safety improve road graduated licensing programs, and safety, such as establishes requirements for driver regulations, such as vehicle size and infrastructure education. Some State DMVs also weight, driver hours of service, and improvements, serve as the primary owners of the medical fitness. law enforcement, statewide crash data. and campaigns State Health Departments to change driver behavior. State Highway Patrols Focus Area: Road User Behavior This is seen in Focus Area: Law Enforcement the types of State health departments also crashes which State highway patrols (also known play an important role in reducing serve as the as State police and State patrols) crash severity. These agencies focus areas of are typically responsible for an SHSP, such operate in every State except Hawaii. as speeding State police patrol highways and statewide trauma center planning. related crashes, enforce motor vehicle laws State health departments provide which are most and regulations. training, certification, and technical effectively assistance for EMS providers, addressed State law enforcement agencies play administer injury prevention through a an important role in reducing the programs, and maintain trauma and combination frequency and severity of crashes. of speed injury databases. Some State health At the scene of crashes, State police enforcement, departments coordinate with other direct traffic, administer first aid, engineering public agencies and community modifications, call for emergency equipment, groups to promote young driver and behavioral write traffic citations, and safety, older driver safety, child campaigns. complete crash reports. passenger safety, and pedestrian State highway patrols also and bicycle safety.

5-8 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS State Safety Plans highest potential to save lives and Coordinated, and Programs prevent injuries. Since 2005, Federal legislation has required States to Comprehensive State agencies use numerous develop, implement,evaluate, and See previous approaches to improve road safety update their SHSP.12,13 page. within their State. Often, they seek The State DOT develops an SHSP to identify State-specific safety in a cooperative process with local, issues and direct Federal or State State, Federal, tribal, and private 12 funding to solve those issues. State sector safety stakeholders. It is agencies take the lead in developing “Strategic Highway a data-driven, multi-year plan Safety Plans: statewide safety plans or programs, that establishes statewide goals, A Champion’s many of which are encouraged or Guidebook to Saving objectives, and key emphasis Lives 2nd ed.,” required by the Federal Government. areas. The development of an SHSP Federal Highway Although States differ in their Administration provides a venue for highway safety (Washington, specific safety improvement efforts, partners in the State to align goals, D.C., October the following plans or programs are leverage resources (i.e., combine 2012), History and developed in every State: Background, http:// Federal and State resources), and safety.fhwa.dot. collectively address the State’s gov/hsip/shsp/ JJ Strategic Highway Safety Plan guidebook/ovrvw. 14 safety challenges. cfm JJ Long Range Transportation Plan An ideal SHSP meets several criteria: JJ Statewide Transportation Improvement Program JJ It addresses engineering, 13 14 management, operation, JJ Railway-Highway “Strategic Highway education, enforcement, and Safety Plan (SHSP),” Crossing Program emergency service elements of accessed August 13, highway safety as key factors in 2013, http://safety. JJ Highway Safety Program fhwa.dot.gov/hsip/ evaluating highway projects. shsp/. Although the HSIP was previously JJ It considers safety needs of, and covered under Federal safety high-fatality segments of, all programs, it should be noted that public roads. the State plays the major role 15 in selecting locations that need JJ It considers the results of “Map-21,” Title safety improvement, designing, State, regional, or local 23 U.S.C. (2012), accessed August 19, and implementing the safety transportation and highway 2013, http://www. improvement, and reporting annually safety planning processes. gpo.gov/fdsys/pkg/ on all the HSIP funded projects that PLAW-112publ141/ JJ It describes strategies to reduce pdf/PLAW- were constructed that year. or eliminate safety hazards. 112publ141.pdf

Strategic Highway Safety Plan JJ It gains approval of the governor of the State or a responsible A State’s SHSP is a statewide- State agency.15 16 coordinated safety plan that provides a comprehensive framework for As mentioned on page 5-5, in order “Highway Safety Improvement Plan reducing highway fatalities and to spend HSIP funds, a State must (HSIP),” accessed serious injuries on all public roads. have a current SHSP, produce a August 14, 2013, An SHSP identifies a State’s key program of projects or strategies to http://www.fhwa. dot.gov/map21/hsip. safety needs and guides investment reduce safety problems, and evaluate cfm. decisions toward strategies with the the SHSP on a regular basis.16

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-9 Long-Range focused on improving safety, such Transportation Plans as widening shoulders or installing rumble strips. Projects included in Long-range transportation plans STIPs must have identified funding (LRTPs) identify transportation sources (e.g., HSIP, State, or local goals, objectives, needs, and funding). The State DOT identifies performance measures over a 20- to projects in areas outside MPOs, 25-year horizon and provide policy such as rural areas and smaller and strategy recommendations urban jurisdictions, for inclusion for accommodating those needs. in the STIP.17 17 LRTPs are prepared at both the State and MPO level. LRTPs are Railway-Highway Title 49, United States Code, § 5304 fiscally-unconstrained and typically Crossings Program present a systems-level approach that considers roadways, transit, The Railway-Highway Crossings pedestrian, and bicycle facilities. Program funds safety improvements LRTP’s have wide scopes; the to reduce the number of fatalities, components of the plan may be injuries, and crashes at public grade 18 18 policy-oriented and strategic or crossings. A grade crossing is a focused on specific projects. The location where a public highway, “Railway-Highway types of improvements range road, street, or private roadway Crossings Program,” accessed August widely, as well. Safety-focused (including associated sidewalks and 9, 2013, http:// improvements in a LRTP may be pathways) crosses a railroad track at www.fhwa.dot.gov/ the same level as the street. These map21/rhc.cfm. directed at infrastructure, such as building new interchanges locations are high-risk spots for or bringing certain highways road users. The United States has more than 200,000 grade crossings.19 19 up to current design standards, or behavioral efforts, such as Types of crossing improvements Railroad-Highway addressing seat belt use or that the Railway-Highway Crossings Grade Crossing aggressive driving. Program implements include: Handbook 2nd ed. Federal Highway JJ Crossing approach improvements: Administration Statewide Transportation (Washington D.C., projects such as channelization, August 2007) Improvement Programs new or upgraded signals on the The Statewide Transportation approach, guardrail, pedestrian/ Improvement Program (STIP) bicycle path improvements near identifies the funding and the crossing, and illumination scheduling of transportation JJ Crossing warning sign and projects throughout the State that pavement marking Improvements: support the goals identified in projects such as signs, the LRTP. STIPs are short-range pavement markings, and/or (typically an outlook of five to ten delineation where these project years) and fiscally constrained, activities are the predominant meaning that the projects must have safety improvements designated funding. While many STIP projects are constructed for JJ Active grade crossing equipment capacity or mobility reasons (i.e., installation/upgrade: projects build a bypass or widen a road), such as new or upgraded flashing there are also STIP projects that are lights and gates, track circuitry,

5-10 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS 20

“Railway-Highway Crossings Program Reporting Guidance,” accessed August 9, 2013, http:// The Railway-Highway Crossings Program funds safety improvements at crossings. www.fhwa.dot.gov/ map21/guidance/ guiderhcp.cfm.

wayside horns, and signal Highway Safety Plan (HSP). The improvements such as railway- HSP establishes goals, performance 21 23 highway signal interconnection measures, targets, strategies, and and pre-emption.20 projects to improve highway safety “MAP-21,” Title 23, U.S.C. (2012), in the State. It also documents the accessed August Highway Safety Program State’s efforts to coordinate with 16, 2013, http:// the goals and strategies in the www.fhwa.dot. Each State administers a Highway gov/map21/docs/ SHSP. However, the Highway Safety title23usc.pdf, Sec. Safety Program, approved by the Program is distinct from an SHSP. 402. U.S. Secretary of Transportation. SHSPs target improvements to The program is designed to reduce infrastructure and road users, and 22 deaths and injuries on the road by are broad in content and context, targeting user behavior through while highway safety programs “MAP-21,” Title education and enforcement focus more on road user behavior.22 23, U.S.C. (2012), campaigns.21 The State conducts accessed August An HSP might address issues such 16, 2013, http:// this program through the State as excess speeds, proper use of www.fhwa.dot. highway safety office. A State is occupant protection devices, driving gov/map21/docs/ title23usc.pdf, Sec. eligible for SHSP grants by having while impaired, and quality of traffic 148. and implementing an approved records data.23

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-11 Local Agencies Charlotte Pedestrian Safety Local agencies, such as city and The City of Charlotte developed its county governments, play an Transportation Action Plan (TAP) in important role in improving road 2011 to describe how to reach its safety safety and identifying and selecting and mobility transportation goals. The transportation projects. These agencies plan emphasized the safety of all road that administer roads at the local level users and included objectives such as constructing 375 miles of new sidewalk by may be called by various names: public 2035.24 To support the goal of pedestrian 24 road agency, department of public safety, Charlotte developed Charlotte works, departments of transportation, WALKS, the city’s first comprehensive The City of Pedestrian Plan. This plan identified new Charlotte or road commissions. Due to their Transportation smaller size, many local agencies strategies to meet the pedestrian safety 25 Action Plan Policy may not have a staff member who is and walkability goals in Charlotte’s TAP. Document, 5 Year Update, August 22, specifically focused on road safety. 2011. The urban nature of their jurisdiction naturally causes their efforts to be and may coordinate with the local focused on different types of road agency to identify potential safety 25 safety topics than a State DOT. improvements and get them installed. Many local agencies also collaborate http://charlottenc. For example, a city transportation gov/Transportation/ department would typically focus on with the State DOT to develop a Local Programs/Pages/ urban elements such as sidewalks, Road Safety Plan. default.aspx transit accommodations, and high At the regional level, metropolitan density access management, where planning organizations (MPOs) plan, as a State DOT would typically be program, and coordinate Federal focused on more rural elements, such highway and transit investments. as high speed curves and isolated When an urban area meets certain intersections. minimum characteristics (e.g., Most safety issues for local streets, population), Federal law requires the intersections, or corridors are the creation of an MPO for the region responsibility of the city or county to qualify for Federal highway or government. These agencies transit funds in urbanized areas. supplement State laws, establish MPOs do not typically own or operate traffic laws in their jurisdictions, the transportation systems in their and determine penalties for jurisdiction. MPOs play a coordination noncompliance. Local law enforcement and consensus-building role in 26 agencies investigate crashes and planning and programming funds for submit crash data to State and Federal capital improvements, maintenance, The Transportation Planning Process agencies. City and county planning and and operations. MPOs involve local Briefing Book, engineering staff help plan and design transportation providers in the Federal Highway planning process by coordinating Administration roads, bike lanes, and sidewalks. Many and Federal Transit local police departments partner with with transit agencies, State and Administration, State police to implement impaired local highway departments, airport 2015 Update, http://www.fhwa. driving, work zone safety, motorcycle authorities, maritime operators, dot.gov/planning/ safety, heavy truck, and safety belt rail-freight operators, Amtrak, port publications/ briefing_book/ education and enforcement programs. operators, private providers of public fhwahep15048.pdf In some States, the State DOT owns transportation, and others within the many of the major roads in the city MPO region.26

5-12 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS Other Safety Partners manufacturing vehicles that had “smart” technologies to Although government agencies have improve safety, such as collision the support of large budgets and warnings and assisted braking. institutional authority to These technologies, which were implement improvements to road not required by the government, safety, they are not the only entities addressed some of the most working to improve road safety. common crash types, such as rear Government agencies work with end crashes. These improvements partners from a variety of fields also set the stage for more to improve the nation’s roadways advanced automated vehicle including those in private industry, designs and technologies. special interest groups, and professional organizations. Insurance Companies Private industry Insurance companies often assist in identifying ways to improve Automobile Manufacturers safety on the nation’s roads. The most notable organization in this Auto manufacturers have a critical respect is the Insurance Institute effect on road safety by designing for Highway Safety (IIHS) and its vehicles that assist the driver in sister organization, the Highway avoiding crashes and that absorb Loss Data Institute (HLDI). These energy in crashes that do occur. are organizations that study road Federal standards stipulate that safety issues and use insurance data vehicles must have certain safety to provide data-based evidence of improvements, such as seat belts, safety by vehicle make and model. air bags, and electronic These organizations are funded stability control.27 However, 27 by a pooled group of insurance auto manufacturers have also companies and associations. IIHS Title 49 of the implemented various non-required United States Code, runs the Vehicle Research Center, safety improvements. These Chapter 301, Motor which conducts crash tests of many Vehicle Safety; improvements typically make use of and Federal Motor vehicle types to encourage auto emerging technologies or materials. Vehicle Safety manufacturers to produce safer Standard (FMVSS) No. 218 For instance, in the early 2000’s, vehicles and inform the consumer auto manufacturers began on vehicle safety ratings.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-13 Special interest groups

Special interest groups are associations of individuals or organizations that promote their common interests by influencing the legislative process at the local, State, and/or Federal levels of government. Many interest groups also serve other functions, such as providing American Council of the Blind services and information to their (ACB) and National Federation of members. Interest groups fill a the Blind (NFB) vital role in advancing the cause of The ACB and NFB represent the safety-related legislation. interests of people who are blind or visually impaired. These organizations A few examples of road safety- work to inform legislators, city and focused interest groups include the State agencies, and the public about AAA Foundation for Traffic Safety, road safety issues that are unique to National Safety Council, Mothers individuals with visual impairment. Against Drunk Driving (MADD), They promote policies and practices the American Council of the Blind, that assist visually impaired individuals in traveling safety and independently. and the National Federation of the These include enhancements, such as Blind. There are many other interest auditory stop announcements on buses groups involved in influencing and accessible pushbuttons that provide transportation and safety legislation. information about street crossing These groups engage signals. in a variety of activities, such as sponsoring independent research and evaluation, These organizations often hold mobilizing citizens to contact their regular conferences that allow legislators in support of or against safety professionals to network, certain pieces of legislation, and share ideas, and gain knowledge disseminating policy reports in from others in their field. The support of or against legislation organizations also provide training affecting the safety of the road users opportunities that help advance and they represent. disseminate road safety knowledge.

Professional organizations There are many professional organizations covering many Professional organizations bring disciplines that relate to road safety. together road safety professionals While this textbook is not intended from common backgrounds or to provide an encyclopedic listing, a spheres of influence to foster discussion and advancement of few examples are listed below. safety issues. Members of these American Association of organizations who recognize State Highway Transportation emerging road safety issues can Officials (AASHTO) use the power of the group to advocate legislation or sponsor AASHTO members consist of research to address these issues. representatives from highway

5-14 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS and transportation departments Governors Highway Safety in the 50 States, the District of Association (GHSA) Columbia, and Puerto Rico. AASHTO GHSA represents the State and provides tools such as Safety territorial highway safety offices Analyst, an analytical software that implement programs to package, and publishes the Highway address behavioral highway Safety Manual, which provides safety issues including occupant an analytical and quantitative protection, impaired driving, and framework for analyzing a road’s speeding. GHSA provides leadership safety performance. AASHTO focuses and advocacy for the States and on emerging safety issues through territories to improve traffic safety, its Standing Committee on Highway influence national policy, enhance Traffic Safety. AASHTO inspired the program management, and promote development of a national safety best practices. plan called Toward Zero Deaths, committed to reducing the number International Organizations of highway fatalities to zero. As of 2017, there is no U.S. Institute of Transportation organization that combines the Engineers (ITE) narrow focus of improving road safety and a broad multidisciplinary ITE is an association of approach. The current inventory transportation professionals of U.S. professional organizations who are responsible for meeting is usually specific to a type of mobility and safety needs. ITE discipline, such as engineering or promotes professional development behavioral science. Looking beyond of its members and facilitates the U.S. borders shows that other the application of technology and countries have formed organizations scientific principles to the safety that bring together many different of ground transportation. ITE’s disciplines to address road safety Transportation Safety Council covers including the following: issues, such as roadside safety, pedestrian and bicyclist safety, and JJ World Road Association (PIARC, work zone safety. after its former name Permanent International Association of Road Association of Transportation Safety Congresses), www.piarc.org/en/ Information Professionals (ATSIP) JJ La Prévention Routière ATSIP focuses on data and is the Internationale (PRI), www.lapri.org leading advocate for improving the quality and use of transportation JJ United Nations Road safety information. ATSIP furthers Safety Collaboration, the development and sharing of www.who.int/roadsafety/en/ traffic records system procedures, JJ Global Road Safety Partnership, tools, and professionalism. Its goal www.grsproadsafety.org is to improve the quality of safety data and encourage their use in JJ International Road Federation, safety programs and policies. www.irf.global

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-15 EXERCISES

JJ RESEARCH a recent road safety project JJ RESEARCH a private sector or industry in your city, county, State, or region. association that works to improve road Identify the roles and responsibilities safety. Prepare a class presentation that of the Federal, State, and/or local includes a brief history of the interest governmental agencies in the project. group, a synopsis of important and Prepare a brief report for a successful campaigns, and a summary class presentation. of its current work. Some examples of private sector or industry associations JJ USE your local, State, or regional include the American Insurance highway department’s website to Association (AIA), the American Traffic determine its most pressing road safety Safety Services Association (ATSSA), concerns. Prepare a brief report that the American Road and Transportation explains the concerns, how the agency Builders Association (ARTBA), the identified them, the proposed remedies, National Association of County Engineers and the agency’s next steps. (NACE), the American Public Works JJ PREPARE a brief presentation that Association (APWA), and many others. summarizes how your local government JJ FIND OUT how professional associations administers roadway programs. Identify like the National League of Cities, the the form of government (city, county, American Association of State Highway municipality, parish, etc.), the local Transportation Officials (AASHTO), the agencies, and their responsibilities to Governor’s Highway Safety Association roadway safety programs. (GHSA), and the Standing Committee JJ RESEARCH a private or nonprofit on Highway Traffic Safety (SCOHTS) interest group that works to improve influence road safety policy. road safety. Prepare a class presentation What are some examples of past that includes a brief history of the interest successful campaigns? group, a synopsis of important and JJ Using the State DOT website, successful campaigns, and a summary RESEARCH your home State’s Highway of its current work. Some examples of Safety Program. Prepare a brief private or nonprofit interest groups presentation that identifies the State and include the Automobile Association describes how it is working to improve of America (AAA), Mothers against roadway safety. You may want to focus on Drunk Driving (MADD), the Insurance the State’s efforts with a particular road Institute for Highway Safety (IIHS), and user or road safety provider. Be sure the American Bikers Aimed Toward to include details about how the State Education (ABATE), and many others. identified the safety challenge(s), how JJ RESEARCH your local, State, or regional the State chose its countermeasure(s), transportation safety planning group. and how its efforts measure against Prepare a brief report that identifies the national performance criteria. group’s current safety goal(s), explains how the group plans to alleviate the safety challenge(s), and describes the group’s strategic communications plan.

5-16 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS CHAPTER 14 IMPLEMENTING ROAD SAFETY EFFORTS Road Safety Research

Road safety practitioners are constantly seeking the most effective means for preventing injuries and fatalities on the road. To accomplish this, they need to understand the nature of the road safety problems and which behavioral or infrastructure countermeasures are the best at addressing these problems. When weighing two possible safety treatments, they need to know which one is more effective (would prevent more crashes) and more efficient (preventing crashes at a lower cost). Additionally, safety practitioners work with a limited budget, so they need to know which safety treatment is more cost effective, that is, how many crashes can be prevented for the same dollar spent. These goals lead to many questions, such as: practitioner. Unit 3 of this textbook JJ What age range should be provides a look at the various types targeted in a young driver of safety data and how they can safety program? be used together. Good research JJ What is an effective strategy analyzes one or more kinds of safety for preventing data to gain knowledge on ways to run-off-road crashes? prevent crashes or decrease injuries when crashes do occur. JJ How many crashes would be expected on one type of road General Types of versus another type? Road Safety Research JJ How many serious injuries The intention of this chapter is not could be prevented by installing to summarize the entire field of additional safety measures at a road safety research, but rather to signalized intersection? provide an overview that will show Research is the key to answering what types of research have been these questions and providing conducted within the topic of quality information to the safety road safety.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-17 RESEARCH QUESTION EXAMPLES

PROBLEM IDENTIFICATION EVALUATION

What are characteristics of crashes What is the safety effect of instituting involving teen drivers? a graduated driver license law?

What type of driver is overrepresented Has the arrival of ride-sharing apps in in alcohol-related crashes? cities reduced alcohol-related crashes? PERSON

What models of vehicle are more What is the effect of an antilock prone to run-off-road crashes? braking system on run-off-road crashes?

What factors are associated with What is the effect of airbags on large truck-related crashes? injury severity? VEHICLE

What road features are associated What is the safety effect of installing with run-off-road crashes? rumble strips?

How does lane width influence What is the safety effect of narrowing driver speed? lanes on urban roads? D

A Are some land development patterns What is the safety effect of controlling riskier from a safety standpoint? road access in dense urban areas? RO ENVIRONMENT

TABLE 5-2: Safety Research Categorization

One way that these road safety of Transportation (FDOT) was research projects can be generally experiencing thousands of crashes, categorized is by grouping them by including many fatalities, in the safety factor they address: the construction work zones and sought person, the vehicle, or the roadway. an alternative to the traditional For each of these categories, safety work-zone barrier. University of research typically focuses either Florida civil engineering researchers on identifying safety problems or hired by FDOT developed a new on evaluating solutions to safety type of portable temporary low- problems. Table 5-2 demonstrates profile barrier that can redirect this classification of safety research cars and small trucks, preventing areas and provides example them from crashing into the work questions that would drive research zone and protecting the passengers 26 studies in each area. in the vehicle. The barrier was advantageous in that it could be University of Florida, Office While this chapter presents broken down into small inexpensive of Technology road safety research in terms of segments that are easy to install Licensing, “Portable 26 Temporary Low- identifying problems or evaluating and move around. Additional Profile Barrier solutions, researchers also play key research was carried out to evaluate (PTB) for Roadside roles in developing new solutions Safety”, UF #11052, this new type of barrier in terms of US Patent 6,767,158 to road safety problems. For criteria like crash performance example, the Florida Department and durability.

5-18 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS Examples of relatively low risk conditions before Road Safety Research obtaining full driving privileges. A new driver would progress The following sections provide through Level 1 (a learner’s stage descriptions and examples of requiring extensive supervised research studies. These examples practice), Level 2 (an intermediate will give the reader a look at the stage which prohibited teenage types of studies that are conducted passengers and driving at night), within each of the six categories and Level 3 (full licensure with shown in Table 5-2. no restrictions). NHTSA funded a group of researchers to evaluate the Research on the Person effect of the GDL program on the Problem Identification crash risk of 16-year-old drivers. The researchers examined Michigan The IIHS sponsored a study to statewide crash data from 1996 examine the characteristics of (pre-GDL) and 1998 and 1999 (post- crashes involving 16-year old GDL). They analyzed the pre-GDL drivers. The researchers used and post-GDL rates of 16-year- crash data from NHTSA’s General old drivers involved in crashes by Estimates System (a national crash unit of the statewide population. database built on sampling from Researchers also compared to crash 28 police agencies around the U.S.). rates of drivers over age 25 to Ulmer, Robert G., They compared crash involvement control for any other trends. They Allan F. Williams, of sixteen-year-olds to that of found that the overall crash risk and David F. other age categories of drivers Preusser, Crash for 16-year-old drivers decreased Involvements of and found that sixteen-year-olds 25% by the year 1999 (two years 16-Year-Old Drivers, were more likely to be involved in after GDL was implemented). They Journal of Safety Research, Vol. 28, single-vehicle crashes and night also found significant reductions No. 2, pp 97-103, time crashes (6:00pm to 11:59pm). in many specific crash types, such 1997. http://www. Sixteen-year-olds were also more sciencedirect.com/ as night crashes and single vehicle science/article/pii/ likely to have received a moving crashes. These findings showed S0022437596000412 violation and been at fault for a a significant benefit to the GDL crash. They were also more likely program and served to support GDL to be accompanied by other teenage 29 implementation in other States. 29 passengers. Researchers also found some indications that drivers Research on the Vehicle Shope, J., L. Molnar, M. Elliott, P. with less on-the-road experience Problem Identification Waller. Graduated (females in this study) were Driver Licensing proportionately more involved in Michigan: Early The design of a vehicle, particularly Impact on Motor 28 in crashes. how well it protects the occupants Vehicle Crashes in the event of a crash, can have Among 16-Year- Evaluation of Solutions Old Drivers. a significant effect on injuries Journal of the In 1997, Michigan instituted its sustained in the crash. A group American Medical Association, Vol. Graduated Driver Licensing (GDL) of researchers from the IIHS 286, No. 13, October, program to address the high rate of investigated the relation of vehicle 2001. http://jama. jamanetwork. fatal crashes involving teen drivers. roof strength to occupant injury com/article.aspx? This program required teen drivers during crashes. They examined articleid=194251 to gain driving experience under crash data from fourteen States

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-19 30 for single-vehicle rollover crashes This result is for the ABS alone; the involving midsize SUVs. They also authors recognized that electronic Brumbelow, M., E. used a rating of roof strength for stability control (a technology which Teoh, D. Zuby, and A. McCartt. Roof each vehicle type in the crash data. automatically applies brakes to Strength and Injury Their findings showed that the individual wheels to keep the driver Risk in Rollover on the road) would soon be paired Crashes. Traffic crush resistance of a vehicle’s roof Injury Prevention, was strongly related to the risk of with ABS for potentially greater 10:252-265, 2009. fatal or incapacitating injury to the crash reductions.31 DOI: 10.1080/ 15389580902781343 occupants. This research identified one statistically significant factor Research on the Road (roof strength) in the severity of Environment rollover crashes. The researchers 31 Problem Identification also recommended the study of Kahane, C., and J. other vehicle factors to determine Dang. The Long- Curves on the road, both horizontal Term Effect of their effect on the severity of and vertical, are known to be 30 ABS in Passenger rollover crashes. problem spots for road safety. Cars and LTVs. National Highway Evaluation of Solutions They are particularly concerning Traffic Safety when they occur together, such Administration, Report DOT HS 811 Anti lock braking system (ABS) is as a horizontal curve at the peak 182, August 2009. a technology that was developed of a hill. FHWA sponsored a study to combat the problem of drivers to identify and quantify the road losing control of their vehicle during and curve characteristics that are hard braking due to locked wheels. associated with higher instances ABS modulates braking power to of crashes. The researchers prevent a vehicle’s wheels from examined curves in Washington locking up. Since this technology State using crash data and roadway requires drivers to employ it characteristics contained in the correctly (i.e., step and hold on the Highway Safety Information System brake rather than pumping), the (HSIS). They analyzed locations Federal Government conducted a where horizontal and vertical curves public information campaign in occurred independently, as well as 1995 to inform drivers how to use locations where both occurred in ABS correctly. The NHTSA sponsored the same place. The researchers a study that took a long term look at developed equations that predicted the effect of ABS from 1995 to 2007. the effect on crash frequency for 32 The researchers used crash data each type of curve combination. from two Federal databases (the These predictive equations included Bauer, K.M. and Fatality Analysis Reporting System road and curve characteristics found Harwood, D.W. Safety Effects and the General Estimates System of to affect the frequency of crashes. of Horizontal the National Automotive Sampling These characteristics included the Curve and Grade sharpness of the vertical curve and Combinations on System) to estimate the long-term 32 Rural Two-Lane effectiveness of ABS for passenger the radius of the horizontal curve. Highways, Report cars, light trucks, and vans. They No. FHWA- Evaluation of Solutions HRT-13-077, found that ABS reduced fatal crashes Federal Highway with pedestrians but increased fatal Rumble strips are expected to Administration, Washington, DC, run-off-road crashes. ABS proved to decrease crashes by generating 2013. be quite effective in reducing nonfatal noise to alert sleepy or inattentive crashes in all types of vehicles. drivers that they are about to leave

5-20 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS How Research Affects Implementation: Motorcycle Helmets

Motorcycle helmets are now a common road safety element to reduce serious head injuries, but they were not always so. The original interest in motorcycle helmets began when Colonel T.E. Lawrence (better known as Lawrence of Arabia) died after suffering a head injury in a motorcycle material (Styrofoam) inside the helmet. A crash. One of the physicians who attended study in 1957 by a physician named George him, Hugh Cairns, was moved by the Snively helped this new type of helmet take incident and began studying the prevalence hold through unusual means – testing six of head injuries among motorcyclists in popular motorcycle helmets on human the British Army. His work ultimately led to cadavers. The Roth and Lombard helmet helmets becoming mandatory in the British with the protective lining was by far the 33 Army and the U.K. most effective in preventing head injuries. Maartens, N., A. Early motorcycle helmets were leather caps Many more studies have documented the Wills, and C. Adams. that did little to protect riders. Then in the effectiveness of motorcycle helmets. This Lawrence of Arabia, 1950s, Roth and Lombard came up with the eventually led to standards for motorcycle Sir Hugh Cairns, 33,34 and the Origin of idea of using a crushable, energy absorbing helmets and universal helmet laws. Motorcycle Helmets. Neurosurgery, Vol. 50, No. 1, January 2002. the travel lane. Rumble strips on Major Road Safety both the centerline and shoulder Research Sponsors and ensure that drivers are alerted no 34 matter which side of the lane they Research Programs depart. FHWA, through a pooled Most road safety research is funded Liu, B., R. Ivers, R. fund from 38 States, conducted Norton, S. Blows, by the government, through state S.K. Lo. Helmets a study to determine the safety or federal agencies. However, some for preventing effect of installing centerline and injury in motorcycle research is also funded by privately riders (review). shoulder rumble strips on rural run companies or foundations. The The Cochrane two-lane roads. The researchers organizations that sponsor research Collaboration, John Wiley and Sons, Ltd. gathered data on roads in three projects are often focused on one January 2008. DOI: States and compared crash category of research. The list below 10.1002/14651858. CD004333.pub3 performance for roads where the presents a look at some of the major rumble strips were installed versus research sponsors and their area of roads without rumble strips. The focus in road safety research. analysis showed that the combined 35 rumble strip strategy was effective Federal Research Sponsors Lyon, Craig; at reducing crashes. As expected, Bhagwant Persaud; Federal Highway Administration and Kimberly Eccles. the greatest crash reductions were “Safety Evaluation for crash types that were related FHWA sponsors research studies of Centerline Plus Shoulder to lane departure including head- on a variety of road safety topics, Rumble Strips.” on crashes (37% decrease), run- and their primary focus is on the Federal Highway off-road crashes (26% decrease), roadway or the built environment. Administration, Report FHWA- and sideswipe-opposite-direction This research investigates the HRT-15-048, 2015. crashes (24% decrease).35 impact of road characteristics on

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-21 road safety and seeks solutions to on drivers, passengers, known safety problems. The FHWA pedestrians, and motorcyclists. Offices of Safety and Safety Research Research sponsored by NHTSA and Development conduct research identifies and measures behaviors to address issues including driver involved in crashes or associated interaction with the roadway, with injuries, and develops and intersection safety, pedestrian and refines countermeasures to bicycle safety, and keeping vehicles deter unsafe behaviors and on the roadway.36 The FHWA Turner- promote safe alternatives. The 36 Fairbank Research Center houses research topics include occupant https://www.fhwa. more than 20 laboratories, data protection, distracted driving, dot.gov/research/ centers, and support facilities, and motorcycle safety, speeding, tfhrc/programs/ 37 safety/index.cfm conducts applied and exploratory and young drivers. advanced research in road safety, Transportation Research Board among other topics. Additionally, 37 FHWA staff participates and The Transportation Research provides input to many other venues Board (TRB) is part of the National https://www.nhtsa. of research around the nation. Academies of Sciences and provides gov/research-data National Highway Traffic Safety advice to the nation and informs Administration public policy decisions. TRB plays a major role in road safety research. NHTSA studies behaviors and It hosts an annual meeting where attitudes in road safety, focusing transportation professionals

How Research Affects Implementation: Safety EdgeSM The ultimate intent of safety research is to provide solid data to affect the way that safety measures are carried out in the real world. The development of Safety EdgeSM is a good example of this.

Drivers who run off the road and then 38 try to regain control often go too far and In the early 2000s, several States (Georgia,

Graham, J.L., over-steer, leading to veering into the New York, Colorado, and Indiana) decided Richard, K.R. , opposite lane or running off the road to install several miles of the sloped edge O’Laughlin, M.K., on the other side. This problem is made as demonstration project. The FHWA Harwood, D.W., worse when the soil is eroded away from sponsored a research study to evaluate the “Safety Evaluation of the Safety the pavement edge, creating a drop off. effect of the sloped edge, now called Safety Edge Treatment” This safety concern was recognized in the EdgeSM, on run-off-road crashes. The results Report No. 1980s, and the 1989 AASHTO Roadside showed a positive effect, and this finding FHWA-HRT-11-024, Federal Highway Design Guide included a recommendation swayed many safety offices in favor of the Administration, for adding a sloped edge to the pavement treatment. Those now in favor of Safety Washington, DC. to assist drivers in regaining control onto EdgeSM worked to get other offices, such as (2011) http://www. the roadway. A few States attempted pavement offices, on board with the idea. fhwa.dot.gov/ publications/ this treatment, but it was not widely Eventually it became a widespread practice, research/ implemented. Through the following and by 2015, forty States required Safety safety/11024/11024. years, other research showed a correlation EdgeSM to some degree in their pdf between drop off crashes and fatalities. design policies.38

5-22 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS from around the world present new research on many different Other Research Sponsors transportation topics. The papers Although the majority of road safety presented at the annual meeting research is funded by government are peer-reviewed, and a portion sources, private companies and of them are published in the organizations also participate in funding road safety research. Prominent Transportation Research Record. examples of these are the IIHS and TRB also maintains standing the American Automobile Association Foundation for Traffic Safety. committees that provide direction to the research field and assist in disseminating research findings. several committees that oversee Committees such as Transportation road safety topics including the Safety Management, Highway Standing Committee on Highway Safety Performance, Pedestrians, Traffic Safety and the Subcommittee Occupant Protection, and many on Safety Management. These others specifically address topics groups decide which research topics related to road safety. TRB manages should be prioritized for funding the National Cooperative Highway under NCHRP. Research Program (NCHRP), described below. State Research Programs State Research Sponsors In addition to participating in large scale research efforts, such American Association of State as NCHRP, State departments of Highway Transportation Officials transportation often fund road (AASHTO) safety research projects on topics AASHTO is the organization behind that are of particular interest to NCHRP. The NCHRP funds many their State. They use portions from road safety research projects each Federal funds that are specially year on a variety of topics that are designated for research projects. integral to the State departments Every State has a different process of transportation (DOTs) and for how the research projects are transportation professionals at conceived and conducted, but all levels of government and the a common arrangement is that private sector. The NCHRP is the State DOT contracts with administered by the Transportation universities in the State to conduct Research Board (TRB) and the research. The research topics sponsored by individual State typically pertain to current road departments of transportation. The safety issues that are high priority research projects are conducted in within the State or issues related to cooperation with FHWA (FHWA). geography, terrain, weather, driver Individual projects are conducted by population, or other such factors contractors with oversight provided that may be particular to that State. by volunteer panels of expert For example, a State in a snowy 39 stakeholders. NCHRP projects cover climate may sponsor a research http://www.trb.org/ a wide range of highway topics, but project on how snowplowing affects NCHRP/NCHRP. there is a specific focus area for the visibility and durability of in- aspx safety.39 AASHTO also maintains pavement reflective markers.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-23 CHAPTER 15 IMPLEMENTING ROAD SAFETY EFFORTS Strategic Communications

A key part of many efforts to improve road safety is sharing safety messages through strategic communications. This chapter provides an outline of the most basic elements of strategic communications that transportation safety professionals should use when working with their communications teams to craft and disseminate messages that seek to improve traffic safety culture. As mentioned in Unit 1, strategic communications programs like public education campaigns are commonly used to improve road user attitudes and awareness.

A strategic communications program involves elements of communications, marketing, and public outreach. These components often overlap and are not easily Public education campaigns like this separated into distinct categories one are commonly used to improve road with unique functions. Strategic user attitudes and awareness. communications is more than the (Source: NHTSA) sum of its parts. Rather, it is a structured methodology that fuses messaging with marketing while visibility public information program garnering public support. “Click It or Ticket” safety belt enforcement campaign. Strategic Several examples demonstrate that communications was a key element strategic communications can result of all of these efforts. in behavioral changes. An effort in the late 1980s to stop impaired Other examples of communications driving resulted in substantial efforts include: decreases in Driving Under the JJ Campaigns with careful pre-testing Influence (DUI) citations. NHTSA and delineation of a target group saw successful results from the that receives the messages. implementation of the “Buckle Up America Campaign” and the National JJ Longer-term programs that Safety Council’s “Airbag and Seat deliver a message in sufficient Belt Safety Campaign” and the high- intensity over time.

5-24 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS JJ Education programs built around what “success” should look like. behavioral change models, using Important questions include: interactive methods to teach JJ What are we trying to achieve? skills to resist social influences through role playing. JJ Do we want people to take a new JJ Public information campaigns action, or do we want people to that accompany other ongoing modify an old behavior? prevention activities. JJ How do we know when we have JJ Programs conducted as part of a achieved our goal (i.e., what are broader community effort or in our target metrics)? support of law enforcement. Establishing measurable goals is An effective strategic an important piece that should be communications program, like any not be overlooked. Having a target effective endeavor, needs a plan. The or measurable goal (metric) makes following are key steps in developing it simpler to gauge the success of a a strategic communications plan that campaign. every road safety professional should know: 2. Identify Target Audience 1. Develop objectives After developing communications objectives, the next step is deciding 2. Identify target audience what populations to target. For 3. Design messaging example, safety professionals must decide if the program should be 4. Select communications channels aimed at the general public or a specific sub-set of the population, 5. Determine budget and resources such as young drivers, pedestrians, 6. Measure results or people who drive aggressively. A message could also be aimed at road Each step of this communications safety professionals and government plan outline is discussed in the officials. In addition to a target sections below. audience or audiences, secondary 1. Develop Objectives audiences may be included. For instance, if the program targets young The first phase in creating a drivers, a secondary audience may strategic communications plan is include the parents of these novice to determine objectives. A well- drivers. designed communications strategy may achieve multiple goals, such 3. Design Messaging as informing the public about Once safety professionals identify the transportation safety issues, target audience, they must determine educating key political leaders what the message will be. A key on their roles in saving lives, and step is to define the problem that encouraging active participation needs to be solved in order to craft from safety partners. the message. Messaging should be To develop objectives, safety designed so that it encourages specific professionals must start by defining actions, and draws upon established

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-25 Watch for Me NC

Watch for Me NC is a comprehensive program run by the North Carolina Department of Transportation (NCDOT) Yield to people in crosswalks. in partnership with local communities. It’s the law. It is aimed at reducing the number of WatchForMeNC.org

pedestrians and bicyclists crashes. 2,000 copies of this public document were printed at a cost of $586, or $0.293 per copy . (07/13) The Watch for Me NC program involves two key elements: 1) safety and educational messages directed toward drivers, pedestrians, and bicyclists, and 2) enforcement efforts by area police to crack down on some of the violations of traffic safety laws. Local programs are typically led by municipal, county, or regional government staff with the involvement (Source: Watch for Me NC) Watch (Source: of many others including pedestrian and bicycle advocates, city planners, law enforcement agencies, engineers, public health professionals, elected officials, school administrators and others. All North Carolina communities are encouraged to use Watch for Me NC campaign materials to improve pedestrian Make room for bikes.

and bicyclist safety in their communities. WatchForMeNC.org

1,400 copies of this public document were printed at a cost of $410.20, or $0.293 per copy . (07/13)

objectives to determine what those 4. Select Communications actions should be. Designing the Channels message will bring about questions like these: “Is the intended action Carefully crafted messages need to a change in safety funding or be conveyed through appropriate policies? Or is the goal a change in channels in order to be effective. user behavior?” Focusing efforts Communications channels include on strategies that connect with the personal and the non-personal. the target audience is particularly Personal channels include the important in today’s environment of advocate channel (advocates tight budgets and scarce resources. championing the objectives of a campaign), expert channel After message development, safety (independent experts making professionals should consider pre- statements to the target audience), testing the message with the target and social channel (word of mouth audience. A pre-test can identify communications). Non-personal points of view of the target audience, channels include media, events, provide unexpected insights or and public outreach – examples reactions that can help further refine of common non-personal messaging, and help determine if the dissemination techniques include, communications plan will improve but are not limited to, the following: the chance of accomplishing the stated objectives. JJ Brochures

5-26 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS JJ Conferences/workshops cover them all. For instance, it may be JJ Dynamic message signs necessary to hire an outside firm to help develop and refine messages and JJ Media advisories tactics, and that should be factored JJ New media (e.g., blogs, podcasts, into the budget. All program expenses Facebook pages) should be tracked to determine how JJ News media events well the budget has been met when measuring results. JJ Newsletters and press releases JJ Public service announcements 6. Measure Results

JJ Print, radio, and television Evaluation of a strategic advertising communications program is JJ Social media essential. Without evaluation, current JJ Websites programs may waste resources and fail to contribute to a road safety Safety professionals must work program’s goals. Evaluations help with the communications team safety professionals learn from to determine the right media outcomes and help them allocate mix, which is the combination of funds in the most efficient manner. communication channels needed to If a program does not meet expected meet communications objectives. Together they must figure out metrics, they should re-examine the which channels -- personal and/ program and/or move the resources to or non-personnel – and which other efforts. tactics will help meet the stated To measure the results of the road safety goals. For example, program, safety professionals must personal channels may work well with government officials, while go back to the objectives and pre- non-personnel channels may determined measurable goals and work best with reaching out to the targets. The original questions in public. Also, a detailed timeline of Step 1 will guide the evaluation of channels and tactics to employ, is the success of the program. Surveys, crucial for implementing a strategic focus groups, and/or one-on-one communications plan. interviews are often good ways of 5. Determine Budget measuring the performance of a strategic communications program. and Resources As far as data allow, safety professionals Implementing a comprehensive should also attempt to compare the communications program requires effectiveness of communication resources like money, staff, and campaigns in the same way that time. Therefore, developing a budget for the program is an integral part they compare the performance of carrying out the plan. Safety of traditional infrastructure professionals should consider every countermeasures. The comparison element of the proposed plan, and will help identify campaigns that are make sure there are resources to both effective and efficient.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-27 CHAPTER 16 IMPLEMENTING ROAD SAFETY EFFORTS Advancing Road Safety

This chapter covers the crucial role However, technical knowledge that safety leaders, champions, is not sufficient for change to and coalitions play in road safety occur. Leadership is necessary management. While the various to ensure technical knowledge agencies and organizations involved is used. in road safety bring unique and JJ Road safety programs and valuable perspectives to the problem of road safety, they also projects compete with other bring competing philosophies public sector priorities. Without and problem-solving approaches. strong leaders to support the Bringing these various entities safety cause, public sector together to develop and implement decision makers might not an effective road safety program consider or prioritize safety. is a challenge. Leadership Activities

The major topics include: Leaders are an instrumental part JJ Leaders of any planning process, and road safety programs are no exception. JJ Champions Leaders bring people together, JJ Coalitions provide essential direction, and motivate people to participate in and Leaders implement the program. Leaders should be engaged and actively Leadership is essential in any field, involved in the process. but it is particularly important in road safety for three major reasons: Consider a few examples of leadership in safety: JJ The safety field is diverse. It draws on the skills of JJ State DOT leaders decide that educators, politicians, advocates, reducing fatal and serious bureaucrats, public servants, crashes should be the first and others. These groups priority of the department. They sometimes work in harmony, garner staff support to make but too often, they work in funding and structural changes isolation. Leaders are necessary to the organization to support for cohesion in a complex, the shift in priorities. multi-stakeholder environment. JJ Law enforcement officers JJ A great deal of technical develop new incentive programs knowledge is available in the to encourage officers to identify safety field regarding the most and arrest impaired drivers. They effective means of addressing the successfully sell the program to contributing factors to crashes. their managers.

5-28 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS Leaders bring people together, provide essential direction, and motivate people.

JJ A trauma nurse initiates a developed, and once developed, is “teachable moments” campaign implemented. They are risk takers, in which nurses teach patients problems solvers, and creative about the risks associated with thinkers committed to doing what drinking and driving. is necessary to advance the cause, which sometimes means breaking JJ A mayor recognizes that many traditional institutional barriers streets in her city are not suitable and balancing competing for safe travel by pedestrians agency priorities. and garners support and funding from the city council to build Leaders are often known as program sidewalks and improve the safety managers, and their activities keep the implementation process on of transit stops. track. They manage the process In each of these examples, the and attend to the day-to-day tasks leaders recognized a need for of arranging, facilitating, and change, acted on the need, and documenting meetings, tracking inspired others to follow. Anyone progress, and moving discrete with drive, dedication, and a good activities through to completion. idea can lead. Leaders are needed throughout all Leadership Traits and Skills stages of road safety development, implementation, and evaluation. Good leaders influence policy They communicate the safety direction, set priorities, and vision and support a collaborative define performance expectations. framework that enables safety They energize the road safety stakeholders to participate actively process and see to it that a plan is in implementation.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-29 Leadership Development It also holds those responsible for safety accountable. Leadership To expand leadership support, begin should recognize that this is an with the safety partners already ongoing process and institutionalize committed to the safety concept and the change in the safety decision- process. Encourage the leadership making culture. of those partners to contact their peers, explain the significance of The safety program manager may their efforts, and marshal support. perform either as a part- or full- Their endorsement of the safety time permanent role; experience demonstrates a dedicated role vision should include encouraging is preferable. staff to stay engaged and building relationships across organizational Champions boundaries and traditional areas of responsibility. Successful road safety programs call for at least one champion to Leadership support affects agencies assist in gathering all critical safety or organizations internally by partners into a collaborative group. granting permission to dedicate time Champions provide enthusiasm and and resources to the safety effort. support for the safety programs.

5-30 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS Like leaders, champions must not be involved in the day-to- be credible and accountable, day management responsibility have excellent interpersonal and for program development and organizational skills, and be implementation, but they are able skilled expediters. to “move mountains” in terms of resource allocation and policy Champion Activities support. The second are leaders Safety champions help secure the who inspire others to follow their necessary leadership, resources, direction. These champions are visibility, support, and commitment people who provide enthusiasm and of all partners. Sometimes the DOT support to transportation project leadership, or the leadership of implementation. They tend to be the primary sponsoring agency, subject matter experts and highly appoints the champion. A safety respected within their own agencies champion can reside at any level and in the safety community. within the organizational structure Succession Planning and can perform various functions. All agencies and organizations For example, a safety champion undergo staff changes, and it is may lead the executive committee essential to train the leaders of that meets periodically to solve tomorrow to ensure that the focus problems, remove barriers, track on safety continues into the future. progress, and recommend further This can be accomplished by action. The role of the executive assigning leadership responsibilities committee is to decide which for program implementation to projects or strategies are funded newer staff and by ensuring that all based on input from the emphasis staff have opportunities to engage area teams, and to prioritize them and lead during meetings and based on benefit/cost analysis, other activities. expected fatality reductions, and the extent to which they address the To ensure continuity when an project’s goals and objectives. individual champion or leader retires, takes a position in another Where relationships are not fully organization, or moves out of State, developed, the champion may a systematic approach to identifying have to put in additional effort to their replacement is necessary. The keep the full range of safety selection process should be based partners committed and on individual skills, leadership actively participating. traits, and the position held within Champion Traits and Skills a stakeholder organization. One way to institutionalize the selection FHWA published the “Strategic of safety committee members is to Highway Safety Plan link their selection to the position Implementation Process Model” they hold within the stakeholder that identifies two types of organization. For example, whoever transportation safety champions.39 assumes the previous safety 39

The first have access to resources champion or committee member’s http://safety.fhwa. and the ability to implement position should also become the new dot.gov/hsip/shsp/ change. In other words, they may committee member.

ROAD SAFETY FUNDAMENTALS UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS 5-31 Coalitions those that are Federally required, such as EMS providers, health and Safety partners and organizations education departments, Motor bring unique and valuable perspectives Carrier Safety Assistance Program to bear on the transportation (MCSAP) managers, local agencies, safety problem. However, differing tribal governments, special interest philosophies, competing priorities, groups (e.g., MADD), and others. and varying business cultures may make collaboration a challenge. With an emphasis on wide-ranging Coalitions are an opportunity for road collaboration that includes many safety leaders and champions to bring external partners, it can be easy to together the various disciplines and overlook the importance of broad agencies and focus on the shared DOT involvement, as well. Early goal of reducing crashes. Whether involvement of planning, design, coalitions are short-term, long- operations, and maintenance will term, or permanent, they offer road enhance the implementation of safety collaborators the prospect safety strategies, especially if they of solving complex issues through are new or experimental. partnerships. Some champions bring partners Safety Partners together by convening a safety summit or meeting. This could be The organizational structure of a large initial kickoff meeting or a agencies and interagency working meeting of the safety working group relationships are important factors or steering committee. It provides to consider when bringing safety an opportunity to learn about each partners together. Rather than of the safety partner priorities and create entirely new committees, understand what they contribute. a champion should build upon Coalitions should give participants existing relationships, interagency the opportunity to describe their working groups, and committees. safety concerns and current programs. This may advance the Many States have functioning discussion of critical safety issues, transportation safety committees, identify opportunities, and forge an such as a TRCC, an Executive Committee agreement on how to proceed. for Highway Safety, or a Towards Zero Deaths (TZD) coalition. Benefits of Collaboration Regardless of how safety partners are brought together and organized Engineering, planning, emergency to contribute to the safety process, response, and behavioral approaches all have roles to play in addressing champions should look for ways to road safety. Professionals in these expand membership to include a various disciplines have different broad range of partners, such as skill sets, and they approach insurance, trucking and motor coach solutions using different methods. companies, fire and rescue, local Dramatic improvements in businesses, and others. roadway safety are more likely to When States implement the result through a combination of Federally required SHSPs, their techniques than from techniques safety partners typically include from a single discipline. This need

5-32 UNIT 5: IMPLEMENTING ROAD SAFETY EFFORTS ROAD SAFETY FUNDAMENTALS for multidisciplinary solutions road safety research, which provides necessitates collaboration. knowledge on identifying safety Unit Summary problems or evaluating potential solutions. Strategic communications Improving road safety is a complex allow all road safety partners to be endeavor requiring the knowledge effective in their efforts to improve and expertise of a wide range road safety, either in communicating of professionals. Road safety to the public or to transportation improvement is a joint effort professionals. across many Federal, State, and local agencies, each with their own Leadership is essential in the road particular focus area. safety field. The diversity of the field, the importance of coordination Federal agencies often play a among disciplines, and the need role in providing funding and to defend safety programs among national cooperation for focused a host of competing public sector road safety efforts. State and local priorities all contribute to the need agencies implement road safety for strong leadership. Successfully improvements, either for roads and implementing road safety efforts intersections in their jurisdiction, or relies on safety champions and on the road users themselves. The coalitions that bring together efforts of these government agencies safety partners from all agencies is supported by a broad base of and disciplines.

EXERCISES

JJ IDENTIFY a road safety leader in your what projects the State implemented community, State, or region. Determine under the champion’s guidance. Be the leader’s area(s) of concern, observe sure to include an assessment of the how the leader engages with the champion’s tenure. transportation safety community, and JJ Coalition building requires a thoughtful, assess the leader’s success. Write a reasoned approach. CHOOSE an brief report summarizing your research. important road safety issue that the Include an explanation for why or why transportation community is still not the leader was successful. studying. Propose a list of coalition JJ FHWA has explicitly stated that a members that could best approach “safety champion” should lead safety the issue from all available disciplines efforts, specifically development of and interests. Be sure to keep the list State SHSPs. Using your home State’s reasonable. In a report, summarize DOT website, RESEARCH past or the safety issue and introduce the present safety champions. Prepare a coalition members. Explain why each brief class presentation that identifies member is critical to the coalition the champion, explains why he or and the expectations for each she was chosen for the role, what the member’s contributions. requirements of the position were, and

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Road Safety Fundamentals is available for free at: https://rspcb.safety.fhwa.dot.gov/rsf/

FHWA, Office of Safety Felix H. Delgado, P.E. [email protected]

FHWA-SA-18-003