CITY LIMITS Setting Safe Speed Limits on Urban Streets

Summer 2020 NACTO City Limits City Limits NACTO

Acknowledgements

NACTO MEMBER WORKING GROUP Lily Reynolds, Deputy Director of Complete ABOUT NACTO NACTO PROJECT TEAM Streets, Philadelphia oTIS

Christopher Cairns, City Transportation Gustave Scheerbaum, P.E., Director NACTO’s mission is to build cities as Corinne Kisner, Executive Director Engineer, City of Orlando places for people, with safe, sustainable, of Strategic Initiatives, Transportation, Kate Fillin-Yeh, Director of Strategy accessible, and equitable transportation Najah Casimir, Communications Manager, Philadelphia oTIS choices that support a strong economy and Zabe Bent, Director of Design City of Cambridge Traffic, Parking & Brad Topol, Interim Vision Zero Coordinator, vibrant quality of life. We do this by: Transportation Seattle Department of Transportation Jenny O’Connell, Program Manager • Communicating a bold vision for 21st Charlotte Castle, Deputy Chief of Staff, Liliana Quintero, Senior Transportation century urban mobility and building Matthew Roe, Technical Lead Managing Directors Office, Philadelphia Engineer, City of Vancouver strong leadership capacity among city oTIS Alex Engel, Communications Manager transportation officials. Kelley Yemen, Director of Complete Streets, Policy Associate Dongho Chang, City Traffic Engineer, Sindhu Bharadwaj, Philadelphia Office of Transportation, • Empowering a coalition of cities to lead Seattle Department of Transportation Infrastructure, and Sustainability the way on transportation policy at the Celine Schmidt, Design Associate Ethan Fawley, Vision Zero Program local, state, and national levels. Coordinator, City of Minneapolis Public • Raising the state of the practice for Works EXTERNAL REVIEWERS street design that prioritizes people Tim Frémaux, Senior Transportation walking, biking, and taking transit. Engineer, Valley and Western District Sarah Abel, Technical Programs Manager, Operations, Los Angeles Department of Institute of Transportation Engineers Transportation Jessica Cicchino, Vice President, Research, NACTO EXECUTIVE BOARD Lacey Hirtle, Senior Traffic Safety Engineer, IIHS City of Vancouver Charlotte Claybrooke, Active Transportation Janette Sadik-Khan, NACTO Chair Principal, Bloomberg Associates Matt Kelly, Vision Zero Specialist, Porltand Program Manager, Washington State Bureau of Transportation Department of Transportation Robin Hutcheson, NACTO President Julia Kite-Laidlaw, Director of Strategic Jackie DeWolfe, Director of Sustainable Director, Minneapolis Department Initiatives, New York City Department of Mobility, Massachusetts Department of of Public Works Transportation Transportation Eulois Cleckley, NACTO Vice President Wen Hu, Senior Research Transportation James Le, Senior Civil Engineer, Seattle Executive Director, Denver Department of Engineer, IIHS Department of Transportation Transportation & Infrastructure Brooke McKenna, Assistant Director for Beth Osborne, Director, Transportation for Street Management, City of Cambridge America Michael Carroll, NACTO Secretary Deputy Managing Director, Office of Traffic, Parking & Transportation Leah Shahum, Executive Director, Vision Transportation and Infrastructure Systems, Zero Network Richard Montanez, P.E., Deputy City of Philadelphia Commissioner for Transportation, Eric Sundquist, Director, State Smart Philadelphia oTIS Transportation Initiative, University of Robert Spillar, NACTO Treasurer Ryan Noles, Senior Transportation Planner, Wisconsin Director of Transportation, City of Austin City of Boulder Veronica Vanterpool, Principal, V Squared Joseph Barr, NACTO Affiliate Member Strategies Ryan Reeves, Vision Zero Program Lead, Representative; Director, Traffic, Parking, & Sustainable Streets Division, San Francisco Transportation, City of Cambridge Municipal Transportation Agency

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Table of Contents Key Terms & Definitions Acknowledgements 2 Key Terms & Definitions 4 Absolute Speed Law: A legal environment in which drivers must never drive faster than the posted speed limit, regardless of what they deem safe for conditions. Speed Limits Conversions 4 Executive Summary 6 Basic Speed Law: A legal environment in which drivers must never drive faster than is safe for present conditions, regardless of the posted speed limit. About This Document 7

Design Speed: The speed on which the geometry or physical elements of the roadway is based. 1 The Need 8 Operating Speed: The speed at which vehicles are traveling along a roadway. Rethinking Safety 11 Posted Speed Limit: The maximum lawful speed as displayed on a regulatory sign. Speed Kills 14 Statutory Speed Limit: The speed limit established under law, which applies in How Speed Kills 15 the absence of a posted speed limit. Designed to Fail: The problem with percentile-based speed limits 18 Target Speed: The highest speed that designers intend drivers to go on a specific Speed Limit Changes Have Big Impacts 22 street or road.

2 The Tools 26 Tools to Change Speed Limits 28 Authority to Change Speed Limits 29 Speed Limits Conversions Combining Tools 31 Case Studies in Lowering Speed Limits 35

10 15 25 40 MPH KPH MPH KPH 3 The Right Speed Limits 40 Recommended Speed Limits 42 15 25 30 50 KPH MPH KPH MPH Default Speed Limits 44

20 30 35 60 Defining Slow Zones 52 MPH KPH MPH KPH Corridor Speed Limits / Conducting Safe Speed Surveys 56

4 Checklists 90

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Executive Summary About This Document

We cannot reduce traffic fatalities on US city setting speed limits in urban areas. In many In 2018, NACTO convened a working group with commercial, residential, or retail uses streets without reducing speeds. places, cities have turned to increased police of major US cities to develop new robust along one or both sides. This guidance is enforcement to compensate for restrictive guidance for setting speed limits on urban also applicable on streets like these in non- More than 35,000 people die in traffic crashes engineering and speed limit setting policies, streets that could provide an alternative to the urban areas. This guidance is not applicable on US roads each year, and millions more are a practice that is not proven to reduce serious highway-focused federal recommendations. on limited access streets, even within cities, seriously and often permanently injured. The injuries or fatalities, and often increases risk Over the course of the following 18 months, or on rural or very low density streets with United States has the highest fatality rate in for Black, Indigenous, and people of color transportation staff from 19 cities helped to limited multimodal use. the industrialized world; double the rate in (BIPOC) on city streets. write and review the guidance and provided Canada and quadruple that in Europe. While Finally, the speed limit setting guidance technical expertise based on their experience traffic fatalities may seem like an intractable This document, City Limits, is intended to contained in City Limits is only one piece of developing speed management strategies issue, city governments have the power to provide city practitioners with guidance on a larger, essential discussion around how and programs and implementing lower speed reduce the frequency and severity of traffic how to strategically set speed limits on urban to make streets truly safe for everyone. limits in their own cities. crashes by reducing motor vehicle speeds. streets, using a Safe Systems approach, Speeding vehicles pose a significant, specific, to reduce traffic fatalities and injuries. The resulting guidance, City Limits, provides and deadly threat, but comprehensive safety Addressing speed is fundamental to making Recognizing that city authority to set speed cities with clear technical and policy guidance on city streets and public spaces involves streets safer. Vehicle speed increases both limits varies by jurisdiction, City Limits offers on setting safe speed limits on city streets. All a more holistic consideration of risks— the likelihood of a crash, as well as the severity three tools for setting speed limits on urban of NACTO’s Member Agencies (81 members from accessibility to gender identity-based of the crash, as it diminishes drivers’ ability streets: at the time of final review) have approved harassment to racial violence. In particular, to recognize and avoid potential conflicts. In this guidance. The technical guidance and speed enforcement as currently practiced addition, on streets with higher speeds and recommended maximum speed limits in this poses additional, disproportionate health higher speed limits, traffic engineers have Setting Default Speed Limits on many document are based on input from NACTO and safety risks especially to Black and fewer design options to increase safety. streets at once. member agencies, academic studies about Latinx people. Manual police enforcement is In cities, transportation agencies have long speeds that minimize conflict and risk, and a less effective way to manage speeds down understood that motor vehicle speed plays a best practices in cities across the world. over time than street design and engineering Designating Slow Zones in sensitive key role in fatal and serious crashes, and have changes, and can create dangerous physical areas. Unlike existing national guidance, City Limits sought to reduce speeds through design and and mental health impacts for Black, focuses on urban streets, which pose the most regulation in order to save lives. But speed Indigenous, and people of color (BIPOC), as challenging scenarios for determining speed limit reductions have remained out of bounds well as other marginalized road users. This Setting Corridor Speed Limits on high limits and are where the majority of pedestrian for many city transportation agencies because resource touches on speed enforcement, but priority major streets using a Safe Speed and cyclist fatalities occur. In this document, authority over speed limits, even on city it is not the focus of this guidance. City Limits Study. urban streets refer to most of the categories streets, is often held at the state level, and is addresses speed limit setting policy which, of streets found in North American cities, commonly tethered to the practice of using the City Limits maps a new path for US cities, paired with street design, is the best tool for including local, primarily residential streets, existing speeds on a street to determine what codifying speed limit setting best practices reducing the health and safety risks posed by mixed use corridors, transit corridors, high the speed limit should be. This flawed model that have been tested and documented in vehicular speeds. density downtown streets, and urban arterials uses the current behavior of individuals to cities across North America. Cities can create determine the speed limit, instead of allowing better and safer outcomes for all by adopting engineers and planners to set the limit at these speed limit setting practices as part of the speed that will create the best, safest their traffic fatality reduction or Vision Zero conditions for all road users. The result is programs. By managing speeds, cities can higher speeds and speed limits over time. save lives.

Practitioners often find themselves with limited recourse to address these challenges because they lack an alternative method for

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Photo: City of New York

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SEATTLE Rethinking Safety

In 2018 alone, drivers killed 36,560 people on US streets are becoming especially US roads and seriously injured millions more.1,2 dangerous for people walking and biking. These tragedies are the result of a failed Between 2009 and 2018, pedestrian deaths approach to traffic safety that prioritizes from traffic crashes in the US grew by 46%, speed and convenience over human lives. reaching a nearly 3-decade high of 7,354 people killed by vehicles in 2018 alone.4,5 Experience from other industrialized countries This rate means that people walking and shows that fewer traffic deaths and safer roads biking are an increasingly large percentage are possible. Rather than focusing on individual of all fatalities on the road. For the past behavior, these countries focus on changing five years, pedestrians and cyclists have the policies and engineering decisions that accounted for almost 20% of all road create unsafe conditions. This technique, also fatalities, despite making up only 11% of known as a Safe Systems approach, is the road users.6,7 And this number is on the rise. guiding philosophy behind the safer streets in From 2008 to 2018, cyclist and pedestrian European Union and Scandinavian countries, fatalities increased by 38% versus a 12% which have, on average, a per capita traffic decline for vehicle occupants.8 fatality rate that is half and a third, respectively, of that in the United States.3 Compounding these statistics, reliance on increased police enforcement to address dangerous driving in the name of “safety” Safety for all road users must be set has contributed to the disproportionate as the foremost goal, and all decisions number of Black people stopped, injured, and killed by the police.9 must be made based on how well they advance work toward zero deaths.

PEDESTRIAN FATALITIES HAVE BEEN STEADILY RISING SINCE 2009

7,000

6,000 killed 5,000

4,000 Pedestrians

2000 2005 2010 2015

Photo: City of Seattle

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In cities, where the vast majority of pedestrians infrastructure to support that speed. PHILADELPHIA and cyclists are killed, transportation agencies Instead of being forced upward over time, have long understood that motor vehicle speeds, and fatalities, would go down as speed plays a key role in fatal and serious they have in the countries that use such crashes, and have sought to reduce speeds approaches. and save lives. But speed limit reductions To reduce traffic deaths and severe injuries have remained out of bounds for many city in the US, transportation policymakers must transportation agencies because authority change their approach. Safety for all road over speed limits, even on city streets, is users must be set as the foremost goal, and often held at the state level, and is commonly all decisions—about speed, infrastructure, tethered to the practice of using the existing allocation of parking and other curbside speeds on a street to determine what the uses, enforcement, and maintenance— speed limit should be. This method results in must be made based on how well they higher speeds and speed limits over time.10 advance work toward zero deaths. By taking If the US approached speed limit setting a holistic, Safe Systems approach to street using a Safe Systems approach, engineers design, cities can reduce speeds, build safer Photo: Charles Mostoller would determine the speed that is safest streets, and save lives. for all people using the street and then build RACISM EXACERBATES THE DANGERS OF SPEEDING

Structural and individual racism exacerbate to a White pedestrian actively crossing in the TRAFFIC FATALITIES ARE DECLINING IN MOST OTHER INDUSTRIALIZED the dangers posed by speed. In their 2019 crosswalk only about 3% of the time versus COUNTRIES, BUT RISING IN THE US11 Dangerous by Design report, Smart Growth 21% of the time for a Black pedestrian.16 America finds that Black, Indigenous, and Finally, relying on traffic stops as a primary 25 Latinx people are more likely than White people method for managing speeds can hinder to be struck and killed by a driver.12 Street larger efforts to improve overall community conditions are often worse in low-income safety on streets and deepen the role 20 neighborhoods and those where people of of transportation in structural poverty, color are the majority. Historically, in many where enforcement targets low-income cities, redlining justified underinvestment in communities. According to the Department 15 public services for communities of color, while of Justice, about half of all interactions with past and current highway siting decisions, Russia police begin with a traffic stop or crash.17 suburban-focused traffic engineering United But data shows that when enforcing traffic States practices, and disinvestment in urban cores, 10 laws, police disproportionately stop Black

Deaths per 100,000 per 100,000 Deaths result in substandard, dangerous streets in people and other people of color, sometimes Sweden Spain predominantly low-income, immigrant, and UK Italy with fatal consequences.18 By focusing only BIPOC communities.13 5 Norway Canada on reducing traffic fatalities at the cost of Mexico Japan Recent studies from Portland State University increasing risk of fatalities due to police Austria Australia Netherlands and the University of Nevada, have found violence and undue stress, transportation 0 racial bias in how quickly or frequently drivers planners, engineers, and practitioners ‘95 ‘97 ‘99 ‘01 ‘03 ‘05 ‘07 ‘09 ‘11 ‘13 ‘15 ‘17 yield to pedestrians in crosswalks.14, 15 In erode their credibility with the communities particular, in higher-income neighborhoods, they serve and undercut the momentum for researchers found that drivers failed to yield safer streets as a whole.

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Speed Kills How Speed Kills

Speed is a central factor in traffic deaths. The Higher speeds are more likely to result in crashes National Highway Traffic Safety Administration because the amount of time a driver has to hit the reports that speed was a factor in a quarter of brakes or swerve decreases at higher speeds, all fatal crashes in 2018.19 As speed limits and while vehicle braking distances increase.23,24 A speeds increase, so do fatalities. Researchers driver going 40 mph travels twice as far as a driver 1 2 from the Insurance Institute for Highway traveling at 25 mph before coming to a complete Crashes at higher speeds Drivers traveling at Safety (IIHS) found that a 5 mph increase in the stop.25,26,27 Research also shows that drivers have are more forceful and thus higher speeds have a maximum speed limit was associated with an less peripheral awareness at higher speeds and more likely to be fatal narrower field of vision 8% increase in the fatality rate on interstates are less likely to see or predict potential conflicts and freeways, and a 3% increase in fatalities such as people crossing the street or children on other roads.20 playing.28 Meanwhile, crashes are more likely to 25 be fatal at higher speeds because these crashes Vehicle speed at the time of impact is directly MPH are more forceful. correlated to whether a person will live or die. 100 O A person hit by a car traveling at 35 miles per As a result, evidence shows that small 45 O

Force MPH hour is five times more likely to die than a reductions in speed result in large safety gains.29 65 person hit by a car traveling at 20 miles per The Highway Safety Manual reports that a 1 mph hour.21 The risk of death at every speed is reduction in operating speeds can result in a 17% higher for older pedestrians and pedestrians decrease in fatal crashes.30 A separate study Speed hit by trucks and other large vehicles.22 found that a 10% reduction in the average speed resulted in 19% fewer injury crashes, 27% fewer High speed crashes are more likely to occur severe crashes, and 34% fewer fatal crashes.31 than crashes at lower speeds and, when they do occur, they’re more likely to be deadly.

THE LIKELIHOOD OF FATALITY INCREASES EXPONENTIALLY WITH VEHICLE SPEED32 3 4 Drivers traveling at higher Vehicles traveling at 100% Hit at 50 mph, speeds travel further higher speeds have Common Speed 75% of people Limits on Urban will die before they can react longer braking distances Arterials 75%

Likelihood 20 50% MPH 63 ft of Death Hit at 32 mph, 25% of people will die Hit at 23 mph, 30 25% 119 f t 10% of people MPH will die

40 164 ft 0% MPH 15 25 35 45 55 MPH MPH MPH MPH MPH thinking braking Impact Speed

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PITTSBURGH

High speed driving is particularly deadly Urban arterials are typically signed for 35- where different types of road users share 45 miles per hour or higher, and are designed space and must interact frequently. In the to support high speeds by featuring wide, US, fatal crashes are disproportionately highway-width lanes, sweeping turn radii, clustered on a small group of high speed, and few places to stop for people to cross. auto-oriented streets, known as urban In many cities, urban arterials often lack arterials. Between 2014 and 2018, urban basic protections for people outside of cars, arterials accounted for 29% of all fatal such as sidewalks, even when bus stops crashes in the US and half (49%) of all fatal are present or when the adjacent retail/ crashes involving people biking or walking, commercial land uses encourage people to Photo: City of Pittsburgh despite making up only 6% of US roadways.33 go there.

TWO TAKES ON SAFETY-FIRST SYSTEMS APPROACHES

INCREASING VEHICLE SIZE COMPOUNDS THE DANGERS OF SPEED Vision Zero saves lives US Aviation makes an impact

In the US, the trend toward larger and they have a taller frame, which Shifting an entire system from unsafe to safe By nearly every measure, commercial vehicles compounds the problems posed increases the likelihood that, if struck, a is not just an aspiration. Many US cities have aviation is the safest transportation mode by excessive speeds. In 2017, 43% of person (especially a child) will be pulled adopted safety-first programs, to varying in the United States. There were 3 fatal pedestrian and cyclist fatalities involved under the vehicle rather than pushed degrees of success. Vision Zero, Injury crashes between 2010 and 2017, compared 38 an SUV, pickup truck or other light onto the hood. Minimization, and Safe Systems programs to 17 fatal crashes in 1960 alone. These truck.34 In 2015, the National Highway affirm safety as the top transportation priority safety gains are the result of systemwide, The US trend toward larger, more Traffic Safety Administration found that and the most effective way to eliminate traffic interdisciplinary approaches to managing dangerous vehicles is only growing. pedestrians are two to three times more fatalities. Establishing a safety-first program: risk on the part of regulators and the SUVs and pickup trucks outsold sedans commercial aviation industry. likely to die when hit by an SUV or pickup > Signals a commitment to zero traffic more than three-to-one in 2019, and than by a passenger car.35 deaths on city streets companies like Ford and Fiat Chrysler In 1997, the White House Commission on > Asserts a belief that such a goal Larger vehicles are more lethal than have announced that they will stop Aviation Safety & Security and the National is attainable smaller ones for two main reasons: they producing the vast majority of their Civil Aviation Review Commission released > Accepts the role of officials, are heavier, which increases the force of sedans and compact cars.36 reports calling for the Federal Aviation engineers, and planners in the impact when combined with speed; Administration (FAA) and airlines to work making streets safer together to reduce fatal accidents.39 In response, the FAA partnered with airlines to CLEVELAND Safety-first programs recognize that although human error is inevitable, fatalities and severe form the Commercial Aviation Safety Team injuries are preventable through street design (CAST), which uses incident data to discern and management choices. Successful safety safety priorities, deploys interdisciplinary programs systematically change the way teams to determine underlying crash streets operate to keep users safe, even when causes, and applies interventions based on individuals make mistakes. their findings.

Sweden has created one of the most In 2009, Continental Flight 3407 crashed, successful Vision Zero programs to date. In killing all 49 people on board and one 1997, when Sweden adopted its Vision Zero person on the ground. Pilot error and fatigue program, there were more than 7 traffic were the listed causes. By 2013, the FAA deaths per 100,000 people. Today, despite dramatically increased both training and more than 20 years of growth in traffic rest requirements for pilots.40 Humans in Photo: Angie Schmitt, @schmangee volume, this number has dropped to 3 people the commercial aviation industry make on Twitter, Cleveland, OH per 100,000.37 mistakes. However, a systems approach to safety has resulted in substantive safety gains across the entire industry.

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Designed to Fail THE PROBLEM WITH PERCENTILE-BASED SPEED LIMITS

Current speed limit setting practice in the US Two issues are at play. First, percentile-based Posting higher speed limits does not increase wider range of speeds. This can increase uses a percentile-based method, typically set models are designed to respond to extremes. compliance with the law. Even when higher the likelihood of crashes because people at the 85th percentile, to determine speeds. When enough people drive faster than the speed limit signs are posted, some number are traveling at increasingly different Traffic engineers record how fast vehicles are set percentile, the model rewards them by of people will still choose to drive 5-15 mph speeds, and increases the likelihood that traveling on a road, determine the speed that instructing traffic engineers to increase the faster than the posted limit. These “high- crashes will be fatal because they occur at 85 percent of drivers are traveling at or below, posted speed. end” speeders travel even faster as speed higher speeds. then set the new speed limit by rounding from limits rise and typically spread out over a Second, people decide how fast to drive based that speed to the nearest 5 mph increment. on both the street’s design and cues such as Traffic engineers who use the 85th percentile the posted speed and other drivers’ speeds. method are instructed to raise the speed limit Researchers originally recommended using USING PERCENTILES TO DETERMINE SPEED LIMITS = 5 vehicles (out of 100) when more than 15% of drivers are driving the 85th percentile approach to determine RESULTS IN INCREASED SPEEDS OVER TIME recorded in speed study faster than posted signs. This method forces posted speeds, assuming that drivers always engineers to adjust speed limits to match travel at reasonable speeds.41 But a growing observed driver behavior instead of bringing body of research shows that drivers base their driver behavior in line with safety goals and the decisions at least partially on the posted speed law. When it comes to safety, this method is limit.42,43 When they see higher posted limits, designed to fail. and see the resulting increased speed of their 50 MPH Percentile-based speed limit setting methods peers, they drive faster too, which results in an fail at keeping people safe because they set a increased speed of the street overall.44 permanently moving target based on current 85th percentile human behavior, not safety. speed 45 MPH People choose their speed depending on posted speed 85th signs and keeping up with percentile other drivers (aka “going the speed Based on observed DRIVERS SPEED 40 speed of traffic”). MPH traffic speeds, cities set new, higher posted Traveling Speed 85th speed limits. percentile 35 MPH speed

NEW POSTED SPEED SPEED STUDY Cities measure the speed of 30 40 traffic and MPH MPH identify the 50th or 85th percentile speed.

1st Speed Study 2nd Speed Study 3rd Speed Study

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RURAL CONNECTICUT

In cities and other urban contexts, time to 45 mph. While other additional factors percentile-based speed limit setting may also have played a role in speeds inching https://portal.

methods are particularly dangerous because up over time, absent any design or land use https://www.flickr.com/photos/sdot_photos/48472932437/ct.gov/DOT/ they are based on outdated research that changes, the increase suggests that the 85th in/photolist-2gRos3r-JKvGUx-FCFnYi-X6Q7rc-XeTjss-qNCj7y-General/History/ 22Aq162-X6Q7oX-24fbPXm-2gzqxCf-Fs1iyb-2heaNTc-F9RfHF- is inapplicable in urban settings.45 The percentile operating speed can shift over time YDvPkW-2gpDWfU-26LhFYP-2782jkJ-JcjwdW-JTaKBN-EFFU3x-Historical- Lty1HD-FPTsKT-2eYkhnj-PYQBtx-pdzXdo-NKmLcp-M4FpVM- 1940s-era research supporting the 85th in accordance with the posted speed limit. Mizxzr-HLVuzC-QLov4C-2cgMt3u-GmW8Ve-VzTaYd-qw8AtG-Merritt-Parkway- HsowEc-PKUEzE-DPMzCq-Pq3bKJ-PKUEfw-YnQFbN-MGtVgT- percentile relied on self-reported crash Notably, this time period in LA corresponded to NKmLoM-2bNarFf-eQ1xmX-2cgMt1f-2a4Laue-Pq3c1o-PYQBwZ-Images data and was conducted on two-lane rural a 92 percent increase in pedestrian fatalities.48 28mz4Eo-Huyy81 highways, devoid of multimodal activity.46 The most commonly cited alternative for But these historic roads are a far cry from the the 85th percentile is USLIMITS2, an online vibrant streets and arterials that typify city Photo: State of Connecticut DOT tool developed by the Federal Highway streets today. In particular, rural roads and Administration that incorporates other factors The research supporting the use of the 85th percentile method was conducted on rural, highways lack the type or volume of conflicts when determining speed limits. USLIMITS2 is two-lane highways. found in cities, such as people crossing the a step forward in that it allows practitioners to street, and people biking, walking, or rolling at also consider the street’s most exposed users. a variety of speeds. They also lack driveways, However, it still relies on the 85th or, more loading, parking, and double-parking. commonly in urban areas, the 50th percentile AUSTIN Los Angeles’ experience with Zelzah Avenue operating speed, which is often still much provides a telling example of the dangers higher than is safe. Relying on a percentile- of percentile-based speed limit setting. based system focused on current driver In 2009, Los Angeles conducted a traffic behavior, rather than a defined safety target speed study and raised the speed limit on to set speed limits, significantly limits cities’ Zelzah Avenue from 35 mph to 40 mph.47 In ability to reduce traffic deaths. 2018, the city again studied existing traffic speeds, and again raised the speed limit, this

Relying on a percentile-based system focused on current driver behavior, rather than a defined safety Photo: Capital Metro

target to set speed limits, significantly limits cities’ But streets in cities are full of people walking, biking, using transit, and driving all in close ability to reduce traffic deaths. proximity. The 85th percentile method for setting speed limits has never accounted for these types of conditions.

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Speed Limit Changes SPEED LIMIT REDUCTIONS ALONE CAN REDUCE SPEEDS AND CRASHES

Have Big Impacts CASE STUDY CASE STUDY TORONTO SEATTLE Rethinking how urban speed limits are set Reducing the posted speed limit unlocks a improves safety for people in a number of variety of engineering and design tools that can ways. Even changing the posted speed limit further increase safety on a street and support In Toronto, Researchers at The Hospital Seattle DOT replaced existing 30 mph sign creates safety benefits and allows other policy goals. Typically, the posted speed for Sick Children found that on streets signs spaced 1 mile apart with 25 mph cities to provide more and better safety of a street dictates what infrastructure and where speed limits were lowered from signs placed 1/4 mile apart on a 1.3 mile treatments, and improve overall quality of safety elements can be included in the final 40 kph to 30 kph, there was a 28% stretch of Greenwood Ave. North / life. street design. For example, if the posted speed decrease in the number of collisions Phinney Ave. North, and saw reductions is 30 mph, a wider curb radius will be required A growing body of research shows that speed between pedestrians and motor in 85th and 50th percentile speeds, as than if the posted speed is 25 mph. The wider limit changes alone can lead to measurable vehicles and a 67% decline in the well as all crashes and injury crashes. curb radius increases exposure and risk for declines in speeds and crashes, even absent number of fatal and serious injuries on During this time, the city did not people walking and biking.51 All too often, enforcement or engineering changes. For streets with speed limit reductions. increase marketing or enforcement, nor essential pieces of safety infrastructure— example, a 2017 Insurance Institute for did they make any engineering changes. raised crossings, bike lanes, corner bulb- Highway Safety study in Boston found that outs—are ironically ineligible for inclusion in a just reducing the citywide speed limit to 25 street redesign because drivers are currently mph from 30 mph reduced speeding overall going too fast. In effect, the street is too and dramatically decreased the instances of dangerous to build safety infrastructure. 40 30 high-end speeding (vehicles traveling faster 30 25 KPH KPH MPH MPH than 35 mph).49 Reducing posted speeds creates opportunities for safer street designs that also support other Similarly, in Canada, researchers at The Decreases in... Decreases in... policy goals. Similar to curb radii decisions, Hospital for Sick Children found measurable often infrastructure that supports transit safety gains after Toronto lowered speed and other sustainable modes like biking and PEDESTRIAN-VEHICLE FATAL & SERIOUS 85TH PERCENTILE limits from 40 kilometers per hour (~25 mph) walking, cannot be included in a design if the COLLISIONS INJURIES SPEED ALL CRASHES to 30 kilometers per hour (~20 mph) on a posted speed is too high. City policies around number of local streets.50 34 MPH 30 safety, economic sustainability, equity, carbon Recent efforts in Seattle underscore emissions reductions, and increased transit, 31 MPH this pattern. There, the Department of bike, and walk mode share are interconnected. Transportation saw significant speed and Rethinking speed limits unlocks the door crash reductions when they lowered the for better design and safer streets, which 21 speed limit to 25 mph and increased the increases opportunities for all. density of speed limit signs on select streets. -28%

All too often, essential pieces of safety infrastructure— raised crossings, bike lanes, corner bulb-outs—are ironically ineligible for inclusion in a street redesign -67% before after before after because drivers are currently going too fast.

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Section 1 Endnotes

1. National Highway Traffic Safety Administration. 15. Coughenour, Courtney, et al. (January 29. Poole, B., Johnson, S., and Thomas, L. 41. Federal Highway Administration (2012). Methods and Fatality Analysis and Reporting System. Retrieved 2017). Examining racial bias as a (December 2017). An Overview of Automated Practices for Setting Speed Limits: an Informational from: https://www.nhtsa.gov/es/research-data/ potential factor in pedestrian crashes. Enforcement Systems and Their Potential for Report. Retrieved from: https://safety.fhwa.dot.gov/ fatality-analysis-reporting-system-fars. Accident Analysis & Prevention, 98, pp. Improving Pedestrian and Bicyclist Safety. speedmgt/ref_mats/fhwasa12004. 96-100. Retrieved from: https://www. Pedestrian and Bicycle Information Center. 2. National Highway Traffic Safety Administration. sciencedirect.com/science/article/abs/pii/ Chapel Hill, NC. Retrieved from: http://www. 42. Hu, W. and J. Cicchino (2019). Lowering the speed Table 54: Persons Killed or Injured, by Person Type S000145751630361X?via%3Dihub#abst0010. pedbikeinfo.org/cms/downloads/WhitePaper_ limit from 30 to 25 mph in Boston: effects on vehicle and Injury Severity, 2017. Retrieved from: https:// AutomatedSafetyEnforcement_PBIC.pdf. speeds. Insurance Institute for Highway Safety. cdan.nhtsa.gov/SASStoredProcess/guest. 16. Ibid. Retrieved from: https://www.iihs.org/topics/ 30. American Association of State Highway and bibliography/ref/2168. 3. World Health Organization. Global Health 17. US Department of Justice (October 2018). Transportation Officials (2010). Highway Observatory data repository: Road traffic deaths. Contacts Between Police and the Public, 2015. Safety Manual. Retrieved from: http://www. 43. Fridman, L., Ling, R., Rothman, L. et al. (2020). Effect Retrieved from http://apps.who.int/gho/data/node. Retrieved from: https://www.bjs.gov/content/ highwaysafetymanual.org/. of reducing the posted speed limit to 30 km per hour main.A997. pub/pdf/cpp15.pdf. on pedestrian motor vehicle collisions in Toronto, 31. Nilsson, G. (2004). Traffic safety dimensions and Canada - a quasi experimental, pre-post study. BMC 4. National Highway Traffic Safety Administration 18. Stanford Open Policing Project. Retrieved from: the Power Model to describe the effect of speed on Public Health 20, 56. Retrieved from: https://doi. (October 2019). 2018 Fatal Motor Vehicle Crashes: https://openpolicing.stanford.edu/findings/. safety. Traffic Engineering. Retrieved from: https:// org/10.1186/s12889-019-8139-5. Overview. Retrieved from: https://crashstats.nhtsa. lup.lub.lu.se/search/ws/files/4394446/1693353. 19. National Safety Council. Motor Vehicle Safety dot.gov/Api/ Public/ ViewPublication/812826. pdf. 44. National Traffic Safety Board (25 July, 2017). Issues: Speeding. Retrieved from: https:// Reducing Speeding-Related Crashes Involving 5. National Highway Traffic Safety Administration. injuryfacts.nsc.org/motor-vehicle/motorvehicle- 32. Tefft, B.C. (2011). Impact Speed and a Pedestrian’s Passenger Vehicles. Retrieved from: https://www. Fatality Analysis and Reporting System. Retrieved safety-issues/speeding/. Risk of Severe Injury or Death. AAA Foundation ntsb.gov/safety/safety-studies/Documents/SS1701. from: https:// www.nhtsa.gov/es/research-data/ for Traffic Safety. Retrieved from: https:// pdf. 20. Farmer, Charles (April 2019). The effects of fatalityanalysis-reporting-system-fars. aaafoundation.org/impact-speed-pedestrians- higher speed limits on traffic fatalities in the risk-severe-injury-death/. 45. Taylor, Brian D. and Yu Hong Hwang (30 June, 2020). 6. Ibid. United States, 1993–2017. Retrieved from: Eighty-Five Percent Solution: Historical Look at https://www.iihs.org/api/datastoredocument/ 33. National Highway Traffic Safety Administration. Crowdsourcing Speed Limits and the Question of 7. National Household Travel Survey (2017). Number of bibliography/2188. Fatality Analysis and Reporting System. Retrieved Safety. Transportation Research Record. Retrieved Person Trips by Mode. Retrieved from: https://nhts. from: https://www.nhtsa.gov/es/research-data/ from: https://doi.org/10.1177/0361198120928995. ornl.gov/ person-trips. 21. Tefft, B.C. (2011). Impact Speed and a Pedestrian’s fatality-analysis-reporting-system-fars. Risk of Severe Injury or Death. AAA Foundation 46. Federal Highway Administration (2012). Methods and 8. National Highway Traffic Safety Administration. for Traffic Safety. Retrieved from: https:// 34. National Highway Traffic Safety Administration Practices for Setting Speed Limits: an Informational Fatality Analysis and Reporting System. Retrieved aaafoundation.org/impact-speed-pedestrians- (2018). Traffic Safety Facts: Pedestrians. Retrieved Report. Retrieved from: https://safety.fhwa.dot.gov/ from: https:// www.nhtsa.gov/es/research-data/ risk-severe-injury-death/. from: https://crashstats.nhtsa.dot.gov/Api/Public/ speedmgt/ref_mats/fhwasa12004. fatalityanalysis-reporting-system-fars. ViewPublication/812681. 22. Ibid. 47. California state law requires localities to evaluate 9. Stanford Open Policing Project. Retrieved from: 35. National Highway Traffic Safety Administration 85th percentile speeds on a given street every seven https://openpolicing.stanford.edu/. 23. Transportation Research Board (2012). NCHRP (2015). New Car Assessment Program years in order for the speed limit to be enforceable. Report 600: Human Factors Guidelines for Road (Docket No. NHTSA–2015–0119). Retrieved According to the law, the city must identify the 85th 10. National Traffic Safety Board (25 July, 2017). Systems. Retrieved from: http://onlinepubs.trb. from: https://www.federalregister.gov/ percentile speed on the street and set speed limits to Reducing Speeding-Related Crashes Involving org/onlinepubs/nchrp/nchrp_rpt_600second.pdf, documents/2015/12/16/2015-31323/new-car- the nearest multiple of five. Passenger Vehicles. Retrieved from: https://www. pp. 5-12. ntsb.gov/safety/safety-studies/Documents/SS1701. assessment-program. 48. California Highway Patrol.Statewide Integrated pdf. 24. American Association of State Highway and 36. Ulrich, Lawrence (12 September, 2019). S.U.V. vs. Traffic Records System. Retrieved from: http:// Transportation Officials (2001). A Policy on Sedan, and Detroit vs. the World, in a Fight for iswitrs.chp.ca.gov/Reports/jsp/userLogin.jsp/. 11. Organisation for Economic Co-operation and Geometric Design of Highways and Streets. Development. Road accidents. Retrieved from the Future. The New York Times. Retrieved from: Retrieved from: https://www.bestmaterials.com/ 49. Hu, W. and J. Cicchino (2019). Lowering the speed https://data.oecd.org/transport/road-accidents. https://www.nytimes.com/2019/09/12/business/ PDF_Files/geometric_design_highways_and_ limit from 30 to 25 mph in Boston: effects on vehicle htm. suv-sedan-detroit-fight.html. streets_aashto.pdf, pp. 56. speeds. Insurance Institute for Highway Safety. 37. International Transport Forum (2019). Road Safety Retrieved from: https://www.iihs.org/topics/ 12. Smart Growth America (2019). Dangerous by Design. 25. National Highway Traffic Safety Administration Annual Report 2019: Sweden. Retrieved from: bibliography/ref/2168. Retrieved from: https://smartgrowthamerica.org/ (August 2015). Safety Facts. Retrieved from: app/uploads/2019/01/Dangerous-by-Design-2019- https://www.itf-oecd.org/sites/default/files/ https://one.nhtsa.gov/nhtsa/Safety1nNum3ers/ 50. Fridman, L., Ling, R., Rothman, L. et al. (2020). Effect FINAL.pdf. sweden-road-safety.pdf. august2015/S1N_Aug15_Speeding_1.html. of reducing the posted speed limit to 30 km per hour 38. US Department of Transportation, Bureau of on pedestrian motor vehicle collisions in Toronto, 13. Cusick, Daniel (21 Jan, 2020). “Past Racist ‘Redlining’ 26. University of Pennsylvania School of Engineering Transportation Statistics (2014). Table 2-9: U.S. Air Canada - a quasi experimental, pre-post study. BMC Practices Increased Climate Buden on Minority (April 2015). Vehicle Stopping Distance and Time. Carrier Safety Data [table]. Retrieved from: https:// Public Health 20, 56. Retrieved from: https://doi. Neighborhoods”. E&E News. Retrieved from: https:// Retrieved from: https://nacto.org/wp-content/ www.bts.gov/archive/publications/national_ org/10.1186/s12889-019-8139-5. www.scientificamerican.com/article/past-racist- uploads/2015/04/vehicle_stopping_distance_ redlining-practices-increased-climate-burden-on- transportation_statistics/table_02_09. and_time_upenn.pdf. 51. Seattle DOT (July 2020). Speed Limit Case minority-neighborhoods/. 39. National Civil Aviation Review Commission Archive Studies. Retrieved from: https://www.seattle. 27. Layton, Robert, and Karen Dixon (April 2012). 14. Goddard, Tara et al. (August 2015). Racial gov/Documents/Departments/SDOT/VisionZero/ Stopping sight distance. Retrieved from: https:// 40. Josephs, L (13 Feb, 2019). The Last Fatal US Airline bias in driver yielding behavior at crosswalks. SpeedLimit_CaseStudies_Report.pdf. cce.oregonstate.edu/sites/cce.oregonstate.edu/ Crash Was a Decade Ago. Here’s Why Our Skies are Transportation Research Part F: Traffic Psychology files/12-2-stopping-sight-distance.pdf. Safer. CNBC. Retrieved from: https://www.cnbc. 52. Federal Highway Administration. Curb Radius and Behaviour, 33, pp 1-6. Retrieved from: https:// com/2019/02/13/colgan-air-crash-10-years-ago- Reduction. Retrieved from: https://safety.fhwa.dot. www.sciencedirect.com/science/article/abs/pii/ 28. National Association of City Transportation reshaped-us-aviation-safety.html. gov/saferjourney1/library/countermeasures/09.htm. S1369847815000923. Officials. (2013). Urban Street Design Guide. New York, NY: Island Press.

24 25 The Need NACTO City Limits

SAN FRANCISCO

Photo: SFMTA

2 The Tools

26 The Tools NACTO City Limits City Limits NACTO The Tools

Tools to Change Speed Limits Authority to Change Speed Limits The tool or combination of tools a city uses or state legislation determines statewide There are three primary tools for will depend on their authority to set speed speed limit setting requirements. In the setting speed limits in urban areas. limits. In some cases, state law already absence of legislative or administrative grants cities authority to set speed limits that requirements, city authority depends on comply with the guidance in City Limits. In engineering practice or law at the city level. others, state departments of transportation

Default Speed Limits* If the city has...

Set default speed limits State-granted on many streets at once. If possible, start by setting citywide default speed authority to lower limits at 25 mph or below. speed limits through If desired or more politically feasible, set default speed a locally-defined limits by category of street (e.g., 25 mph on arterials, 20 process or across mph on non-arterials). many streets at once.

*Applicable on all streets— major, minor, and shared Use a Safe Speed Study (see page 58) to lower speed streets / alleys limits below the citywide or category default on high- crash or otherwise high priority corridors. Consider using a Safe Speed Study to evaluate a batch of similar streets to lower speed limits on many streets of one type all at once (e.g., local streets). Slow Zones

Designate slow zones in sensitive areas. Designate slow zones. Slow zones can be linear (along a street) or cover all streets within a specific neighborhood or business district.

If state or local legislation prevents any of the above, but conducting Safe Speed Studies and lowering default limits is desired, seek the authority to do so.

If the city has...

Corridor Speed Limits* Limited authority Seek a written change in practice (leveraging City to lower speed limits Limits may help). Set corridor speed limits on using a locally- high priority major streets defined process or using a Safe Speed Study across many streets Request that some streets be exempt from the 85th (see page 58). at once. percentile requirement (e.g., streets near schools or other sensitive areas like parks or neighborhood downtowns). *Applicable on major streets only Once the authority is established, see actions above.

28 29 The Tools NACTO City Limits City Limits NACTO The Tools

Cities that have authority to set default speed to use a locally-defined process such as the limits have a number of options to improve Safe Speed Study method outlined on page Combining Tools safety on their streets. In some cities, setting 58, that is different from the 85th percentile the default limit citywide is the most effective method. In some cases, cities have used this Cities can combine these proactive speed management approach. Citywide defaults provide a uniform, same tactic to set default citywide or category- strategies to create safe conditions for their city. predictable limit that applies everywhere. based speed limits by conducting “bulk studies” They are relatively easy to implement and on a representative sample of similar streets in easy to explain to the public. Citywide limits order to assess the appropriate speed for that Default Limit can be combined with slow zones and with category of street. Slow Zones EXAMPLE COMBINATION: CITY A (e.g., schools, Priority corridor limits on specific corridors to address In the states where jurisdictions must set speed parks) Corridors conditions where a speed lower than the limits on most streets based on 85th percentile City A has explicit authority to set default 25 citywide default is necessary. MPH speeds, some cities have requested exemption speeds and has chosen to set a citywide 20 20 In cities where there is clear differentiation from using the 85th percentile for specific streets default limit of 25 mph on all streets. In MPH MPH between major arterial streets and local or (for example, streets identified in a high-injury addition, they have identified a few high- minor streets, cities may choose to set speeds network analysis). In these places, robust crash, crash corridors and have set 20 mph corridor by street type or category. Category-based fatality, and injury data collection is particularly limits on those streets to reduce fatalities limits allow cities to address significantly important to make the case for exemptions. and injuries. They also have established 20 different street contexts but still create mph slow zones in key areas around schools In almost all states, cities have authority to a predictable regulatory environment for or parks to provide additional protection for create school slow zones. For example, in drivers. Like citywide defaults, category-based children. California, which codifies the use of the 85th defaults can be combined with slow zones and percentile method to determine and enforce with corridor limits on specific streets. speed limits on streets across the state, the Category 1: Category 2: In some states, cities do not have explicit Vehicle Code allows all local jurisdictions to EXAMPLE COMBINATION: CITY B Arterial Non-Arterial authority to set their own default speed limits. lower speeds in school zones that meet specific These cities have different playbooks for criteria. In 2019, Sacramento used this authority City B has explicit authority to set default aligning speed limits with their safety goals. to reduce speed limits from 25 to 15 mph on 225 speed limits and has clear differentiation 25 20 street segments across the city, even without between major or arterial streets and minor MPH MPH In states where the process for engineering the explicit authority to reduce default speeds or local streets. They have chosen to set studies is not codified in state law or practice, citywide. category speed limits at 25 mph for arterials cities have asked for (or assumed) permission and 20 mph for non-arterials. Like City A, they may choose to also establish slow zones in key areas. SACRAMENTO

EXAMPLE COMBINATION: CITY C Category 1: Category 2: Priority Residential Arterial Streets City C does not have explicit authority to set default speeds. The state requires a 20 25 20 speed study but does not lay out an explicit MPH MPH MPH process. They have chosen to conduct a bulk engineering study and to use a locally- defined process for setting speeds by street category. At the same time, using authority to set speed limits on a case-by-case basis, Photo: City of Sacramento they have conducted a Safe Speed Study to determine appropriate speed limits for a few priority corridors.

30 31 The Tools NACTO City Limits City Limits NACTO The Tools

RECENT NOTABLE

LEGISLATIVE CHANGES OREGON MINNESOTA Implementing the speed limit tools Oregon (Senate Bill 558) allows all cities in Minnesota Statute (Section 169.14, Subd. 5h - Speed recommended in this guidance may require the state to establish a 20 mph speed limit limits on city streets) allows cities to establish state-level legislative permission. A growing on all non-arterial streets in residence speed limits on city streets based on the city’s safety, group of US states have passed legislation districts under city jurisdiction. Rule 734- engineering, and traffic analysis. Speed limits must be set granting cities the flexibility to set safer 020-0015 allows the use of 50th percentile in a consistent and understandable manner. speed limits. These supportive policies studies instead of 85th percentile studies generally take one of two forms: on non-residential streeets.

Authority to set context- sensitive speed limits using a locally-defined process.

Several states have passed laws that enable cities to create, adopt, and utilize an approach for setting urban speed limits that places safety as the top priority. Cities that leverage this authority do so in different ways, often by lowering default limits on MASSACHUSETTS some or all streets and also by updating local engineering guidance to redefine Massachusetts (MGL c. 90 § 17C) allows speed study procedures. “thickly settled” cities and towns to adopt a WASHINGTON STATE 25 mph default speed limit by ordinance for all streets unless otherwise posted. Cities and Washington State has two pieces of towns can also set 20 mph safety zones, which enabling legislation that, together, allow they can use their own criteria to create. cities to set safe speed limits:

RCW 46.61.415 allows local agencies to establish/alter maximum limits on local streets. NEW YORK STATE Authority to reduce default New York State Assembly Bill 10144/Senate WAC 468-95-045 is a modification to speed limits. Bill 7892 amended section 1642 of the Vehicle the State MUTCD that provides local and Traffic Law to allow New York City to set a Some states have passed laws that explicitly jurisdictions with considerations about speed limit of 25 miles per hour, down from 30 allow cities to lower their default citywide what requirements they need to meet to mph, on streets that are not part of the State speed limits (e.g., from 30 mph to 25 mph) or revise the posted speed limit. speed limits on a specific category of streets highway system. This was followed by NYC (e.g., “residential streets” at 20 mph). Local Law 54 of 2014, which enacted a citywide speed limit of 25 mph unless otherwise posted.

32 33 The Tools NACTO City Limits City Limits NACTO The Tools

Case Studies POLICY HURDLES A city’s ability to change speed limits is impacted by rules and practices around in Lowering Speed Limits enforcement, signage, and design requirements.

NEW YORK Enforcement A city’s ability to enforce the posted speed limit depends on whether speed limits in the state are Absolute, Prima Facie, Basic Speed Law, or a combination of the three. When drivers are ticketed in a state with absolute speed limits, the ticket will typically stand on face value. In states with prima facie, or presumed, speed limits, drivers Photo: Logan Hicks can contest tickets in court on the basis that their speed was safe for the conditions. In basic speed law states, drivers are required only to travel at a safe speed, regardless of the posted speed limit. A growing Recognizing the importance of lowering speed limits to improve safety, a number of cities body of evidence shows that drivers respond to posted speed limits have successfully amended their speed limits in recent years. The four cities highlighted even without changes to enforcement; cities may want to make speed below present interesting lessons learned for other municipalities looking to lower speed limit changes even when enforcement is difficult. limits on their streets.

Signage SEATTLE In some states, a city must install a sign on every block if the posted In 2016, Seattle lowered its default speed limit from 25 to 20 mph on neighborhood streets speed limit is anything other than the citywide default. This is feasible and from 30 to 25 mph on arterials. The City has also begun to reduce speed limits within when the city lowers the limit on a small number of segments, but urban villages, where lots of people walk, bike, drive and use transit. becomes prohibitively expensive at a large scale (e.g., across all residential streets). Resources: Seattle DOT Speed Limits Website, Seattle DOT Blog

NEW YORK CITY Design In some states, cities must implement physical design changes to In 2014, New York City lowered its default citywide speed limit from 30 to 25 mph, which streets in order to justify lower speed limits. Requiring engineering complemented a Neighborhood Slow Zone program implemented in 2011. changes before cities can change the posted limit can make it difficult Resources: 2014 NYC Vision Zero Action Plan, Borough Pedestrian Safety Action Plans, for cities to change speed limits on a large number of streets because Families for Safe Streets of the cost. Other cities must reduce speed limits before they can make design changes, since the design speed is set in relation to the posted speed on a given street. CAMBRIDGE In 2016, the City of Cambridge lowered its default citywide speed limit from 30 to 25 mph. In the years since, Cambridge has leveraged authority to further reduce speed limits to 20 mph in Safety Zones to reduce speed limits to 20 mph on nearly every street in the city.

Resources: City of Cambridge Speed Limits Website

PORTLAND

In 2018, Portland lowered the default speed limit on residential streets from 25 mph to 20 mph. This change complements 20 mph speed limits in business districts.

Resources: Portland Bureau of Transportation Speed Limits Website, 50th Percentile Allowance on Non-Residential Roads

34 35 The Tools NACTO City Limits City Limits NACTO The Tools

CASE STUDY CASE STUDY SEATTLE NEW YORK CITY

Photo: City of Seattle Photo: City of New York

In October 2016, the Seattle City Council support their request. SDOT also included a New York City has worked for over a decade passed a new bill in June 2014 authorizing New passed an ordinance to lower the default variety of stakeholders during the process on comprehensively reducing speeds on York City to lower its citywide speed limit. The speed limit from 25 to 20 mph on 1,250 miles —the transportation director, a city council streets across its five boroughs. In 2011, the City promptly took action, and a new citywide of neighborhood streets and the default member, a lawyer from the law department, City installed its firstNeighborhood Slow speed limit of 25 mph went into effect in speed limit from 30 to 25 mph on arterials. the city traffic engineer, and a public Zone: a program that revamps small (about 1/4 November of the same year. This change was the result of a months-long engagement specialist. square mile) residential areas with low traffic In the same legislative session, the State legislative process initiated by Seattle DOT volumes and minimal through traffic, with 20 Since the law passed, SDOT has built on the Legislature also granted New York City leadership. mph on-street markings, signs, speed humps, momentum of reducing speed limits across permission to establish an automated speed and other traffic calming treatments. This To build their case for lower speed limits, the city to leverage existing state-level enforcement program with a limited number of program quickly expanded to over two dozen Seattle DOT (SDOT) staff compiled two authority to reduce speed limits on 3 high cameras located in school zones. The program neighborhoods, increasingly demonstrating documents. The first was a detailed history crash corridors using a context-sensitive was successful, with speeds lowered by an the large demand for safer streets across the of the city’s 1934 decision to reduce speed engineering study. They are also leveraging average of over 60 percent in camera locations. city. limits to 25 mph on arterials and 20 mph on both of these tools to reduce speed limits at a In 2019, the City obtained new authority to residential streets, and their 1948 decision neighborhood scale in particular zones. In 2013, family members of people killed expand this program more than five-fold, from to raise the default maximum speed across in traffic crashes in New York joined with 140 to 750 active zones. the city from 25 to 30 mph. The second was a City Council members and local agencies data-based justification for lower speed limits Neighborhood to petition the State Legislature to reduce Streets in 2016. In this document, SDOT made the case Arterials speed limits. At the time, the citywide speed Neighborhood that the built environment, the city’s Vision Three limit was 30 mph, the lowest allowed by state Slow Zones, Citywide Zero commitment, and recent mode shift away 25 20 High-Crash law. The campaign hit political hurdles and MPH School Zones Limit from driving and toward walking, biking, and MPH Corridors the State took no action. taking transit all signaled a need for lower, The next year, New York City rolled out its safer speed limits. SDOT also included speed 20 25 Vision Zero Action Plan, which called for MPH MPH and safety data from all of their recent Vision City Hall to lead a campaign to reduce the Zero pilot projects. citywide speed limit to 25 mph. In November 2016, the new law went into WIth the combined advocacy of a years-long effect. This campaign was a success in large campaign by local safe streets advocates, as part because of the data that SDOT used to well as sustained pressure from the Mayor’s Office and city agencies, the state legislature

36 37 The Tools NACTO City Limits City Limits NACTO The Tools

CASE STUDY CASE STUDY CAMBRIDGE PORTLAND

https://www.travelportland.com/things-to-do/neighborhoods-regions/

https://commons.wikimedia.org/wiki/File:Harvard_square_2009j.JPG

Photo: City of Cambridge Photo: City of Portland

In 2016, the City of Cambridge lowered presence of vulnerable users, schools, parks, In 2018, Portland City Council approved an After a speed limit change is approved, but speed limits to 25 mph citywide and began and senior centers, among other factors. ordinance that lowered the speed limit on all before installing new signs, City of Portland implementing 20 mph safety zones in 2018. Implementation of a Safety Zone on streets residential streets to 20 mph, a change that staff notify neighborhood residents about Cambridge—along with other cities and towns under municipal control does not require State resulted in reductions on 70 percent of the the speed limit changes, along with officials in Massachusetts—have the right to set authorization. city’s street network. at the local transit agency, which notifies their operators. speed limits for “thickly settled” areas under Oregon state law also allows the city to the state’s 2016 Municipal Modernization Act. In 2019, using this authority, the City of Cambridge embarked on an effort to reduce implement a 20 mph speed limit in business Where possible, City of Portland staff work to Prior to this reform, the default speed limit in speed limits to 20 mph on most streets. At the districts and to lower speed limits on specific coordinate speed limit reductions with street thickly settled areas was 30 mph and required time of publication, Cambridge has successfully non-residential streets pending approval from redesigns, such as road reorganizations. a speed study to change a speed limit. But reduced speed limits to 20 mph on the majority Oregon DOT in each case. However, Portland frequently reduces speed limits on streets without any expected when a new Governor was elected in 2015, of streets in the city. In Portland, there are 228 miles of non- near-term changes in street design or his office asked all municipalities how the residential arterials with speed limits between enforcement. legislature could update state regulations to 35 and 45 mph where most road deaths occur. Default Limit make cities more effective. Among the asks Effective May 1, 2020, the Oregon DOT began for “Thickly was a request for greater local authority in Safety using a revised speed setting methodology for Settled” Areas Zones Default Limit for all Business setting speed limits. streets like these in urban areas that weighs residential streets Districts The law allows any city or town to adopt 50th instead of 85th percentile speeds, and citywide default limits of 25 mph for areas 25 20 that better accounts for the presence of MPH MPH that meet the definition of thickly settled exposed road users, street design, and land 20 20 MPH MPH (homes or businesses spaced 200’ or less use characteristics. This important change apart) and safety zone limits of 20 mph with came after years of coordination between local government approval. The definition of City of Portland staff and Oregon DOT staff to safety zone is broad, taking into account the develop a revised methodology for determining speed limits on non-residential streets.

38 39 NACTO Setting Safe Speed Limits NACTO Setting Safe Speed Limits

3 The Right Speed Limits PORTLAND

Photo: City of Portland The Right Speed Limits NACTO City Limits City Limits NACTO The Right Speed Limits

Recommended Speed Limits

This document recommends maximum speed limits of 10-25 miles per hour for most city streets, increasing to 35 mph only in select, limited cases. The maximum recommended speed limit for any shared street or alley is 10 mph, and the maximum recommended speed limit for any minor street is 20 mph. The maximum recommended speed limits are based primarily on speeds that minimize risk to pedestrians and cyclists.52

SHARED STREETS & ALLEYS MINOR STREETS MAJOR STREETS 20 25 MPH MPH

On major streets, where conditions vary widely, cities can conduct a Safe Speed Study to determine the safest maximum speed limit (see page 58). In urban areas, a Safe Speed Study will most often result in a recommended maximum speed limit 10 20 25 of 20 or 25 mph for major streets.

30 35 MPH MPH MPH MPH MPH For streets that have well-protected places for people to walk and bike, and that are in low density areas with primarily manufacturing and residential uses, cities may find that a 30 or even 35 mph speed limit is appropriate. However, these higher speed limits should be used sparingly and only in cases where safe conditions can be met.

42 43 Default Speed Limits NACTO City Limits NACTO Setting City Limits Safe Speed NACTO Limits

Default Speed Limits

Applicable on all streets—major, minor, and shared streets / alleys

BOULDER

Photo: Kevin J. Krizek, Professor, University44 of Colorado Boulder 45 Default Speed Limits NACTO City Limits City Limits NACTO Default Speed Limits

Default Speed Limits Citywide Speed Limits Default citywide speed limits, or “unless Recommended otherwise posted” speed limits, provide a default citywide jurisdiction-wide speed limit in effect at speed limit: all times and on all streets, except where a different speed limit sign is in place. These are generally the easiest speed limits to implement, and are usually enacted through law.

Setting or lowering default citywide speed limits is an inexpensive, scalable way to quickly improve safety outcomes, and establish a 25 basis for larger safety gains. Default citywide limits also provide consistent expectations and messages about speed across the jurisdiction, MPH which is easy for drivers to follow. Default Citywide Speed Limit Category Speed Limits

Cities have two options for setting default on a large number of streets below what speed limits: citywide or by street category would be allowable citywide (i.e., 20 mph on (e.g., major, minor, alley). minor streets vs. 25 mph citywide).

Citywide speed limits are generally easier If cities have the authority to set default to implement and may be easier for drivers speed limits, they should decide whether to to follow. However, in cities where there is implement citywide limits or category limits clear differentiation between major arterial based on what makes the most sense given streets and local or minor streets, setting the local conditions. speed limits based on category of street can sometimes allow cities to lower speed limits

Top: The City of Boston lowered the default citywide speed limit to 25 mph in January 2017.

Bottom: In April 2020, the City of Atlanta voted to lower the default citywide speed limit to 25 mph.

46 47 Default Speed Limits NACTO City Limits City Limits NACTO Default Speed Limits

Category Speed Limits MAJOR STREETS A 25 mph speed limit on urban multi- If unable to set a category speed Category speed limits apply speed limits places where site-by-site analysis is lane streets has demonstrable safety limit for all major streets, cities to specific categories of streets based necessary. Depending on the city, setting benefits for all users.53, 54 Major streets should conduct a Safe Speed Study for high-priority major streets on on broad classes, such as major streets, speed limits by category might be more feature a combination of high motor an individual basis. See Safe Speed minor streets, and alleys, allowing cities politically feasible than setting a default vehicle traffic volume, signalization of Study section on page 58. to set a small number of speed limits citywide limit. If setting categories based major intersections, and an inherently that apply to nearly all streets. This on major and minor streets, practitioners multimodal street environment. simple categorization scheme allows should develop definitions for these cities to quickly adjust speed limits on streets that are easy to use based on most streets, and frees up resources existing local data. to focus on high-crash corridors or Major streets are often characterized by: Recommended category speed limit > Signalized intersections > Multi-lane downtown one- way and downtown two-way for Major Streets: > Few, if any, all-way stop streets, as well as many MAJOR intersections STREETS: 25 neighborhood main streets, MPH multi-way boulevards, > At least two formal (marked) and transit boulevards as motor vehicle traffic lanes, described in the NACTO and usually more 25 Urban Street Design Guide > Frequent transit stops MPH

> Moderate to high motor MINOR 20 vehicle volumes STREETS: MPH

SHARED STREETS 10 & ALLEYS: MPH

48 49 Default Speed Limits NACTO City Limits City Limits NACTO Default Speed Limits

MINOR STREETS SHARED STREETS & ALLEYS

A 20 mph speed limit on minor streets supports safe movement and contextually appropriate Shared street surfaces where people are expected to walk in front of motor vehicles or against design on the majority of city streets.55 Since minor streets tend to have either very low volumes oncoming motor vehicles call for the lowest category speed limits. Especially in places where large or operate at the speed of the most cautious driver, cities can apply a category speed limit to vehicles routinely enter shared street spaces, speed limits even lower than the recommended 10 minor streets without detailed review of street characteristics. mph may be advisable.

A 10 mph speed limit is also appropriate for dead ends, laneways, some service/parking/access roads along multiway boulevards, and other streets where walking, playing, or public space activities are expected in the roadway. Minor streets include physically small streets where low speeds Recommended are often already present, as well as low-vehicle-volume streets category speed limit with few or no transit stops. for Minor Streets: Minor streets are often characterized by: Recommended

> A single moving vehicle > Yield streets, neighborhood category speed lane (one- or two-way) streets, some residential limit for Shared boulevards, one-lane 10 > Two moving vehicle lanes 20 Streets & Alleys: downtown one-way and but fewer than 6,000 MPH two-lane downtown two- MPH vehicles per day way streets as described > A “minor” or “local” in the NACTO Urban Street definition in a citywide Design Guide street typology or > Lateral, service, or access street plan roadways along multiway > Stop controls, all-way stop boulevards controls, or yield-controls at multiple intersections

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Defining Slow Zones

SEATTLE

Photo: City of Seattle 52 53 Defining Slow Zones NACTO City Limits City Limits NACTO Defining Slow Zones

Defining Slow Zones

Slow zones are specifically designated elevated collision rates or sensitive land areas with slower speeds than otherwise uses such as schools or parks. Cities similar streets in the same jurisdiction. should create slow zones based on Neighborhood-scale or site-specific their own location-specific needs, but zones are useful for addressing high- several types of slow zones are relatively priority areas such as areas with common.

Photo: City of Boston

Neighborhoods & Districts Neighborhood slow zones and district speed zones are implemented at a neighborhood- wide or district-wide scale. Sometimes these are also called Safety Zones or Neighborhood 20 mph Zones. The recommended maximum speed limit for these zones is 20 mph, and they are often accompanied by either vertical traffic Photo: City of New York calming elements or specific markings.

School, Park, & Senior Areas School, park, and senior area slow zones, as well as slow zones in other sensitive environments, encourage slow speeds in areas with a high concentration of people who are at special risk on the street. In these zones, speeds on major streets may be set as low as 15 mph. Time-of-day school speed limits can be used when the school is an uncharacteristically sensitive place compared with the rest of the street (e.g., a 15 mph limit is appropriate near Photo: Scott Kocher, City of Portland a school on a major street that would otherwise default to 25 mph). Downtown Downtown slow zones or safety zones are a form of district speed zones in high density downtown areas or neighborhood downtowns where conflict is normal and should be expected, even on major streets. The recommended maximum speed limit for these zones is 20 mph.

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Corridor Speed Limits

Applicable on major streets only

SAN FRANCISCO

Photo: SFMTA 56 57 Corridor Speed Limits NACTO City Limits City Limits NACTO Corridor Speed Limits

Setting Speeds on How to Conduct a Safe Speed Study There are four main components of a Safe Speed Study: collect data, analyze existing Major Street Corridors conditions, determine how to manage speeds down, and evaluate changes.

In some jurisdictions or on certain types of will require lower speed limits since the risk of streets, cities may be required to conduct a a crash is high, while somewhat higher speeds 1 Collect Before Data speed study to determine the appropriate can be tolerated on low conflict, low activity Begin by collecting data about corridor conditions and crash history. speed limit. In other places, cities may want to streets.56 conduct a speed study to justify lower speed limits on high-crash corridors below what This section provides step-by-step guidance they are typically authorized to do through for conducting a Safe Speed Study on major citywide or category mechanisms. In these street corridors. Safe Speed Studies should 2 Analyze Existing Conditions be used whenever a corridor speed study is cases, a Safe Speed Study is the appropriate Analyze the corridor, focusing on the frequency of conflict and the amount of activity, required or desired and should be used in lieu tool to use. and use the risk matrix on page 63 to determine the appropriate posted speed. of a percentile-based speed study. Safe Speed Studies are a contextually sensitive tool for determining the correct speed limit for a major street corridor. The To minimize the risk of a person being Safe Speed Study methodology analyzes 3 Determine Best Option for Speed Management conflict density and activity level, among killed or seriously injured, cities Decide on the best option to manage speeds along the corridor using the decision other contextual factors, to determine the should set speeds based on conflict tree on page 73. speed limit that will best minimize the risk density and activity level. of a person being killed or seriously injured. In general, high conflict, high activity streets 4 Conduct an Evaluation Evaluate speed management efforts through pre- and post-implementation LONGBOAT KEY, FLORIDA data evaluation.

A Safe Speed Study should be conducted A Safe Speed Study can also be performed for the longest relevant segment of a street for a large area or district. As with corridor corridor. If a corridor changes significantly at studies, it is not necessary to record data a specific point, it can be divided into two or on every block within the district. Instead, more segments. district-wide corridor speed limits can be set based on an assessment of a typical Cities should avoid studying every block or street within that district. In most cases, every segment of a long corridor. Instead, selecting 20 to 30 representative blocks at cities should identify key locations for study random will provide a reasonable sample and select the lowest practicable speed limit Photo: The Observer of speeds for a category of similar streets, for the longer segment to manage both safety regardless of the size of the city. and legibility along the corridor.57

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1 Collect Before Data

Collecting before/after data allows cities to When using crash report forms to assess DATA TYPES better understand the need for changes and the issues on a corridor, it is important to helps them to more clearly communicate remember that these reports are often project benefits and impacts to the public. inconsistent. The US does not have a uniform Existing speeds: how fast drivers are Before implementing a speed management crash reporting form or protocol across traveling on the street. Cities should project or policy, cities should collect and jurisdictions. In addition, most crash report evaluate a range of metrics, including evaluate data such as existing speeds, forms lack a way to record the secondary 40 50 60 30 70 high-end speeding, speeding, standard speeding opportunities, fatal and serious crash factors, such as speed or road design, 20 80 10 90 deviation, median speed, and 85th injury crashes, and conflict counts. More that contribute to the incident. percentile speed (see page 85). information about collecting and using data According to the National Highway Traffic to improve safety is provided on page 82. Safety Administration, speed is a major Each type of data provides different factor in 25% of traffic fatalities.58 In 2018, information. For example, information on eight percent of fatal crashes were primarily speeding opportunities and conflict counts due to speeds being “too fast for conditions,” Speeding opportunities: locations where indicate the potential for a serious crash and the other 17% were due to some other drivers are comfortable exceeding a while a history of serious or fatal crashes type of speed-related issue. However, there safe speed because of the design and indicates an existing problem that could be is evidence suggesting that speed may be an environment of the street. resolved with lower speeds. Before/after even larger contributor to the rising US fatality evaluation data is needed for understanding rate than the national statistics show. the conditions on a corridor but is not essential to determine what the new speed limit should be.

Fatal and serious injury crashes: a five- year history (if possible) of all crashes that resulted in a fatality or a serious injury, including the location of the crash and x the circumstances of the crash (e.g., left turning vehicle, sideswipe, etc.).

Conflict counts: how often two people or vehicles are on a collision course and must take evasive action to prevent a crash.

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2 RISK MATRIX: CONFLICT DENSITY AND ACTIVITY LEVEL Analyze Existing Conditions The framework below summarizes a method the passive 85th percentile speed study that for determining maximum safe speed limits the MUTCD recommends for highways. based on the density of conflict points and When determining a safe speed limit for a major The following pages provide thresholds for level of activity on a major street. On urban street, there are two primary considerations: each activity and conflict density level, and streets where cities are required to conduct apply these thresholds to example streets in a study to determine the correct speed limit, North America. they should use this framework instead of

CONFLICT DENSITY:

CONFLICT DENSITY ACTIVITY LEVEL HIGH CONFLICT MODERATE LOW CONFLICT How frequently potential conflicts How active a street currently is ACTIVITY LEVEL: DENSITY CONFLICT DENSITY DENSITY arise on a given street or is expected to be

A conflict exists when a normal interaction, Crashes that cause fatalities or serious such as crossing the street while turning injuries are generally the result of conflicts 20 20 25 vehicles yield, is so close and at such a speed happening at speeds that are too high for a MPH MPH MPH that a crash would happen unless sudden human body to endure. Therefore, streets action is taken. In urban conditions, this is with a greater number of potentially serious HIGH ACTIVITY usually a factor of how separated modes are, conflicts and a higher level of activity should and what the crossing demand is. have lower speed limits.

20 25 30 MPH MPH MPH

MODERATE ACTIVITY

25 25 35 MPH MPH MPH

LOW ACTIVITY

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CONFLICT DENSITY

Two primary factors determine how + = frequently potential conflicts between motor vehicles and people walking or MODAL CROSSING CONFLICT bicycling arise on the street: MIXING POINT DENSITY DENSITY

MODAL MIXING CROSSING POINT DENSITY

How much physical separation the street offers How closely spaced intersections people walking, biking, and rolling along the street. and other crossing locations are.

Typical modal separation patterns in urban contexts: Typical crossing point density patterns in urban contexts:

HIGH MODAL MIXING MODERATE MODAL MIXING LOW MODAL MIXING HIGH DENSITY OF CROSSING MODERATE DENSITY OF LOW DENSITY OF (LITTLE OR NO SEPARATION) (MODERATE SEPARATION) (FULL SEPARATION) POINTS for bicyclists, CROSSING POINTS for CROSSING POINTS for pedestrians, and motor bicyclists, pedestrians, bicyclists, pedestrians, No sidewalks or sidewalks > > Urban Street Design > If designated as a bike vehicles and motor vehicles and motor vehicles directly adjacent to moving Guide (USDG)-compliant route, a sidewalk compliant motor vehicle traffic sidewalk, and/or a with the Urban Street > 3 or more “through” or “X” > 1-3 “through” or “X” > No “through” or “X” curbside loading/parking Design Guide plus a intersections (signalized intersections (signalized intersections (signalized Bicycle traffic expected to > lane and sidewalk vertically and horizontally or unsignalized), “T” or unsignalized), “T” or unsignalized), “T” use a mixed-traffic lane or protected bike lane, or a intersections, driveways, intersections, driveways, intersections, driveways, a designated shared bike- If designated as a bike > shared-use path/trail curb cuts, or other crossing curb cuts, or other crossing curb cuts, or other motor vehicle lane (e.g., route, a marked bike lane points per 1/4 mile points per 1/4 mile crossing points per 1/4 mile sharrows) or better > If not designated as a bike route, a full sidewalk > If not designated as a bike that also legally permits route, a full sidewalk that bicycle use also permits bicycle use > Passengers exiting parked or loading vehicles are not directly in motor vehicle traffic lanes

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APPLYING A CONFLICT DENSITY ANALYSIS *Page TK contains a set of checklists that practitioners can use to apply these ON EXAMPLE STREETS concepts in practice to determine the safest speed limits for their streets.

Example Street A Example Street C

Photo: NACTO Photo: NACTO

+ = + =

Minimal separation for Short blocks: HIGH HIGH CONFLICT USDG-compliant sidewalk: Moderate length blocks: MODERATE MODERATE cyclists: HIGH MODAL MIXING CROSSING POINT DENSITY DENSITY MODERATE MODAL MIXING CROSSING POINT DENSITY CONFLICT DENSITY

Example Street B Example Street D

Photo: Google Photo: Google

+ = + =

Full separation for cyclists Very low demand for vehicular LOW CONFLICT Minimal separation for Short blocks: HIGH HIGH CONFLICT and pedestrians on multi-use or pedestrian crossing: LOW DENSITY cyclists: HIGH MODAL MIXING CROSSING POINT DENSITY DENSITY path: LOW MODAL MIXING CROSSING POINT DENSITY

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ACTIVITY LEVEL & LAND USE APPLYING AN ACTIVITY LEVEL ANALYSIS ON EXAMPLE STREETS Activity levels influence the rate at which potential conflicts occur at any given site on the street. Activity can be measured directly where data is available, or through land use and transportation network proxies. Most urban streets are either high activity or moderate activity. This guidance intentionally does not set quantitative activity thresholds. Practitioners seeking to utilize quantitative Example Street A thresholds should determine and set those based on what works well in their cities and what goals they are trying to meet.

Typical activity conditions and scenarios include: Photo: NACTO

Downtown context with high-density residential, commercial, and retail land = uses along both sides of the corridor HIGH ACTIVITY MODERATE ACTIVITY LOW ACTIVITY HIGH ACTIVITY Streets with lots of existing Streets with moderate existing Streets with minimal or expected pedestrian or expected pedestrian activity, expected pedestrian activity, active public spaces, moderately used public spaces, volumes, minimal expected important bike routes or some existing or expected bike or planned bike activity, low Example Street B planned bike routes, high traffic, frequent driveways, curbside demand, and few, if curbside demand, and high curbside parking/loading, and any, transit stops density of transit stops moderate density of transit Low density industrial stops > > Downtown / Central and residential streets Business Districts > Moderate density residential and commercial streets > Retail corridors > Streets with light retail High density residential > activity and commercial streets > Mixed use corridors

Photo: Google

Mixed used corridor with moderate = density commercial land uses

MODERATE ACTIVITY

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COMBINING ANALYSES ON EXAMPLE STREETS APPLYING AN ACTIVITY LEVEL ANALYSIS (CONTINUED...) + High activity streets with a high potential for conflict are the riskiest and command the lowest speed limits. Meanwhile, low activity streets with a relatively low potential for conflict may allow for slightly higher speed limits.

Example Street C

Example Street A

20 + = MPH HIGH CONFLICT HIGH ACTIVITY DENSITY

Photo: NACTO Example Street B

Moderate density = residential street 20 + = MPH MODERATE ACTIVITY HIGH CONFLICT MODERATE DENSITY ACTIVITY

Example Street D Example Street C

25 + = MPH MODERATE MODERATE CONFLICT DENSITY ACTIVITY

Example Street D Photo: Google up to

Low density manufacturing and commercial land uses + = 35 = MPH on both sides of the corridor LOW CONFLICT LOW ACTIVITY DENSITY LOW ACTIVITY

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3 Determine Best Option for Speed Management SELECTING A SPEED MANAGEMENT OPTION

The Safe Speed Study will identify the “before” data about the street (described recommended speed limit for a particular in “Collect Before Data” on page 60) to street (or category of street). This determine the street’s current operating Is the street’s recommended speed limit will either be speeds. One of four situations will be operating speed lower than or the same as the existing apparent after conducting a Safe Speed at or below the posted speed limit. Cities should collect Study, as shown on the next page. maximum safe speed?

TOOLS FOR SPEED MANAGEMENT Yes No

A speed management program seeks to reduce both the overall number of vehicles exceeding the target speed and the even more dangerous high-end speeders.

Is the Is the Signs & Markings posted posted Signs and markings are necessary speed speed to communicate the speed limit and limit... limit... encourage safe speeds.

Design & Operations ...within ...higher than ...within ...equal to or higher Street design and operational changes are recommended operating recommended than operating the most effective method for managing range? speed? range? speed? speeds. Street design is self-enforcing, making it a particularly powerful tool.

No priority MPH MPH Automated Enforcement speed action Automated speed enforcement can be a useful component of speed management. Reduce the Use design and Reduce speed limit. posted speed operations to limit to the manage the recommended speeds down to level the speed limit or lower. Messaging & Education Use design and Marketing campaigns and education operations to programs support cities’ efforts to reduce manage speeds speeds through design and policy. downward over time.

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DESIGN & OPERATIONS DESIGN & OPERATIONS IN PRACTICE Street design and operational changes can reduce the number of opportunities drivers have to speed and reduce the top speeds at which motorists are comfortable driving. Most street BEFORE & AFTER - 10TH ST., ATLANTA design techniques reduce speeding in one of, or a combination of, three ways:

Making speeding Reducing motor vehicle lane Adding gateway treatments physically impossible, width to increase discomfort or ‘arterial slowpoints’ that usually through raised at higher speeds.64 create visual cues to reduce elements. speeds.

Arterials and other large urban streets > Adding street trees, shrubbery, or other present unique challenges for speed neighborhood elements to indicate a management. These streets typically different environment. Photos: City of Atlanta feature high traffic volumes, higher posted > Adding speed cushions, raised speeds, both signalized and unsignalized intersections with gradual slopes, speed crossing points, and multiple lanes. In total, humps, or other bus- and emergency- arterials account for nearly a third of fatal vehicle-compatible raised elements.61 MASSACHUSETTS AVENUE REDESIGN - CAMBRIDGE crashes in the US, despite covering only 6% of roadways.59 To address these challenges, > Converting turn lanes into pedestrian cities will often need to deploy both design safety islands or curb extensions. (street cross-section) and operational > Repurposing under-utilized lanes for (signalization) tools to produce the necessary other modes or other needs. speed reductions. Combined, these tools can help the city achieve harmony between Examples of operational changes include: design speed, target speed, and the speed limit.60 > Reducing the length of signal cycles or green signal time on the major street, particularly at non-peak times.62 Examples of design changes include: > Reprogramming signal timing for a lower > Reducing the number of general-purpose progression speed, usually 2-3 mph motor-vehicle lanes. With fewer lanes, below the target speed (for both one- off-peak vehicle capacity can be more way and two-way streets) or breaking closely matched to vehicle volume using progressions into shorter distances (for signal timing methods. two-way streets).63 Photo: City of Cambridge > Narrowing lanes, using excess space to add in-lane bus stops or bicycle or pedestrian facilities.

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SIGNS & MARKINGS SIGNAGE & MARKINGS IN PRACTICE Communicating new speed limits via signage and markings is essential for effectively managing speeds. Laws and policies about where speed limit signs should be placed vary from city to city. Placing SEATTLE NEW YORK CITY identical speed limit signs on every block of a corridor where the speed limit never changes is costly and does not have proven speed-management benefits. However, preliminary studies out of Seattle show that increasing sign density to one sign every 1/4 mile from one sign every mile does result in lower speeds and fewer crashes. At a minimum, cities should follow the guidance below about speed limit signs, making specific decisions about sign density and placement based on local context.

Cities with default speed limits or Cities with slow zones should Cities with major arterial category speed limits should post post the limit for that zone at slow zones and high-crash “Speed Limit X Unless Otherwise gateways into the designated corridors can post signs on Photo: Bruce Englehardt65 Photo: City of New York Posted” signs at gateways into the area. On-street markings those streets to reinforce the city: highway off-ramps before can also be utilized at the importance of adhering to an intersection, major streets points where the speed limit the speed limit. BOSTON at city limits, bridge and tunnel changes or at key entrances entrances, ferry terminals, and to slow zones. airport car rental facilities. Signs should be placed on any street that diverts from that default limit.

Photo: City of Boston

Top left: Seattle DOT posts these signs at entrances into the city.

Top right: NYC DOT identifies arterial slow zones using special signage.

Bottom: Boston uses signs and on-street markings to alert drivers that they are entering a 20 mph slow zone.

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AUTOMATED ENFORCEMENT AUTOMATED ENFORCEMENT IN PRACTICE

There is a long history of police officers using In particular, ASE programs are more effective NEW YORK CITY traffic stops to target people of color in the at reducing speeding than manual enforcement United States.66 A Black driver is up to four because cameras are consistent and predictable times more likely to be stopped by a police for drivers. Data from NYC’s speed camera officer than a White driver, and once stopped, program shows that, on average, daily violations Black drivers are up to five times more likely at typical camera locations decline over time to be searched than White drivers.67 In the as drivers become aware of the cameras and US, enforcement has come to be the domain drive more responsibly.71 NYC DOT also found of the police, and police departments are an that between 2014-2016, 81% of drivers do active partner in most, if not all, Vision Zero not receive more than one violation, further programs. However, recognizing the biased evidence that the cameras created an overall and sometimes deadly practices of US police behavioral change.72 forces, some cities and national organizations When developing ASE programs, cities should are reconsidering the role of police in making keep several primary considerations in mind. streets safe. Some options include: increasing First, while ASE technology itself may be emphasis on street redesign, automated speed impartial, cities must think critically about enforcement or cameras, and more recently, camera placement to avoid undue impacts moving traffic enforcement responsibilities out on certain neighborhoods or communities. of police departments and into other agencies. For example, cities often find that low A growing body of evidence in places like income communities and communities of Photo: Max Touhey73 Seattle, Boston, and Toronto shows that drivers color experience higher than average serious respond to posted speed limits even without injury and fatal crashes due to bad street any enforcement efforts. On streets where design or underinvestment, leading them to TORONTO operating speeds are consistently higher disproportionately site cameras in those areas. than the posted limit, cities should prioritize Instead, in siting speed cameras, cities should changes to street geometry over other tools. simultaneously use crash data hotspot analysis Changing the design and operations of streets to prioritize locations for street improvement to better match desired speeds and posted projects, and evaluate regularly to determine if speed limits can often diminish the need for cameras are still necessary once the street has any enforcement, and is ultimately the most been changed. In addition, cities should layer effective way to reduce speeds, fatalities, and multiple data points into camera placement injuries. analysis, including crashes and serious injuries, and the presence of schools, daycares, parks, Automated speed enforcement (ASE) can be an and recreation and senior centers. effective tool for reducing operating speeds, especially in locations where data shows that Second, cities should never use ASE to generate there are frequent speed-related fatal and revenue. Instead, ASE should only be a tool for serious injury crashes.68 Studies find that reducing speeds and/or achieving compliance cameras reduce the percentage of speeding with the posted speed limit. Especially when vehicles by 14-65% percent, and serious injury contracting with private ASE vendors, camera and fatal crashes by 11-44% percent.69 Results programs should be evaluated based on Map: City of Toronto from NYC’s speed camera program found that, reductions in speed, not number of tickets in the zones where cameras were installed, issued. The distribution of camera locations, total crashes declined by 15%, total injuries by as well as the messaging behind enforcement, Top: A speed limit sign on Queens Boulevard in New York signals that speed limits are enforced by 17%, fatalities by 55%, and excessive speeding should match the goals of the program. camera in some parts of the city. violations by 60%.70 Bottom: Toronto has an interactive online map that allows residents to see all active red light and speed camera locations.

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MESSAGING & EDUCATION MESSAGING & EDUCATION IN PRACTICE

Communicating speed limit changes to the sports teams, news stories, and op-eds. PORTLAND public is essential to a successful speed Free promotional materials such as buttons, management program. Communications stickers, and yard signs can extend the campaigns should begin well before reach of an educational campaign beyond implementation begins and continue after traditional media channels and outlets. For changes are in place. These campaigns serve example, Portland, Seattle, Minneapolis, a dual purpose, reminding the public about and others have distributed “20 is Plenty” the policy rationale for reducing speeds— yard signs as part of an education campaign reducing traffic fatalities—while also about new 20 mph speed limits on residential preparing residents for the changes they will streets. see on their streets. City transportation departments should Communications campaigns around speed also look to incorporate speed reduction Graphic: City of Portland limit changes should always link speed information into other city-issued collateral, reductions with safety, constantly reminding including materials distributed by other the public, elected officials, and the media agencies. For example, prior to reducing NEW YORK CITY MINNEAPOLIS that reducing speed limits is a critical tool the citywide speed limit, New York City DOT for reducing traffic deaths. Many effective added messaging about the new 25 mph limit campaigns focus on the people who are to the backs of all municipal parking meter harmed by excessive speed, putting faces receipts. to the numbers. Others focus on reminding Finally, community and advocacy partners drivers that even small changes in their speed are essential to successful campaigns. In can increase the probability of surviving a New York, Families for Safe Streets, a group crash. made up of the families and survivors of Cities should be relentless and creative traffic crashes, regularly met with city and when spreading the word about speed limit state-level lawmakers and was instrumental changes. Examples include: TV, radio, and in pushing the NY State legislature to pass online ads, billboards, bus shelters, mailings, legislation authorizing a lower citywide speed cross-promotional campaigns with local limit.74 Photo: NACTO Photo: City of Minneapolis

SANTA MONICA

Photo: City of Santa Monica

From top, clockwise: Portland’s Vision Zero website includes graphics that clearly describe the relationship between speed and safety; Minneapolis Public Works disemminates “20 is Plenty” yard signs to spread the word about new lower speed limits in residential areas; Santa Monica uses brightly colored yard signs to remind drivers that children are present in this area; and New York City reminds drivers about the citywide speed limit on the back of municipal parking meter receipts.

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4

Conduct an Evaluation CHANGES IN HIGH-END SPEEDING 40 50 60 30 70 20 80 Determining the effectiveness of a speed limit In collecting post-implementation data and 10 90 On city streets, the most substantial risk Because high-end speeding is set to a specific change or safety project, and making further conducting project evaluations, cities should comes from high-end speeding, even if it threshold that does not change with the speed adjustments as necessary, is essential to remember that drivers typically adjust to is typically only a small percentage of total limit, this metric allows for apples-to-apples reducing traffic fatalities. In addition, project speed limit changes slowly and therefore traffic. As a result, changes in the number comparisons before and after a project or from data that shows how speed limit changes operating speeds may not change at all in of high-end speeders is a primary metric site to site. The prevalence of high-end speeding reduce speeding and can reduce fatalities is the short-term. As tempting as it is to try to for determining the efficacy of a speed limit is a better indication of risk than 85th percentile essential to making the case for future safety produce immediate results, cities should change or safety project. speed or the number of speeding vehicles, projects. focus on reporting 6-month and 1-year after since there is sometimes a ‘long tail’ of high- High-end speeding is measured as the number data for operating speeds to ensure a robust end speeders.76 Well-done speed management Cities should collect post-implementation data, or percent of drivers exceeding specific, high- and accurate evaluation.75 Transportation can result in a dramatic change in high-end mirroring the data that was collected before risk speed thresholds (e.g., over 30 or 35 mph, department leadership should prepare elected speeding, even when 85th percentile or median the project began, to conduct a full evaluation or greater than 10 mph over the target speed officials, policy makers, the media, and the speeds do not change dramatically. of their work. This data includes operating for most streets), in a typical 24 hour period. public for some “lag-time” between project speeds, traffic incidents—paying special implementation and evaluation and results. attention to fatal and serious pedestrian and cyclist injuries—conflict points, and speeding opportunities. CASE STUDY

RAINIER AVENUE, SEATTLE

KEY METRICS Speed management and street design changes can substantially reduce the amount of high- 2015 2016 Key metrics for determining the effectiveness of a speed limit change or safety project include: end speeding on a street. On Rainier Avenue speed speed limit: limit: in Seattle, a 4-lane-to-3-lane conversion Change in the number of high-end resulted in up to a 16% decrease in median 30 25 MPH MPH 40 50 60 or top-end speeders; change in 30 70 speed, and up to an 81% decrease in drivers 20 80 operating speed 77 10 90 exceeding 40 mph.

Change in the number of speeding opportunities 50TH PERCENTILE SPEED, SPEEDERS TOP END SPEEDERS NORTHBOUND (PERCENT SPEEDING) (DRIVERS EXCEEDING 40 MPH)

84.1% 4.1% 33.4 -16.2% MPH Change in the number of people 28.0 -52.4% killed or severely injured x MPH -80.5% 40.0%

Change in conflict counts 0.8%

‘15 ‘16 ‘15 ‘16 ‘15 ‘16

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CHANGES IN SPEEDING AND OPERATING SPEEDS 40 50 60 30 70 ANALYZING SPEED DATA 20 80 10 90 Changes in the total number of people When necessary, the speed of the median speeding and the overall operating speed or 50th percentile driver can be used to provide information about the typical or understand the typical experience on a Methods for Documenting Speeds median experience on the street or corridor. street. Assuming traffic along the corridor This metric is important to capture because is distributed normally, the majority of Single-point speed studies help identify Speed profiles show the range of it is the simplest. However, unlike high-end drivers will cluster around the median. A high-end speeding locations. Handheld speeds found along a street, making it speeding, the number and percent of drivers large difference between the median and radar, fixed-location radars such as those easy to identify where vehicles speed exceeding the speed limit definitionally 95th-percentile speed can indicate a high used for automated speed enforcement, up or slow down along a corridor. This changes as the speed limit is reduced, so prevalence of high-end speeders or that speed feedback signs, and multi-tube data is increasingly available from city policy makers should be careful when using there are too many opportunities to speed. vehicle counters are all sources of single- fleets or third-party providers. this metric to explain the impact of a project. point speed data of varying quality and sample size.

DETROIT Metrics for Documenting Speeds Several metrics are applicable to Safe Speed Studies on urban streets and before-after evaluation.

XX MPH XX MPH

High-end speeding: Speeding: The percent Standard Deviation: The number or percent or number of drivers The standard deviation of drivers exceeding exceeding the speed limit. of speeds indicates how specific, high-risk speed much faster the high end thresholds. (e.g., over 25 of vehicle speeds are mph, over 30 mph, over from the low end. A large 35 mph). A decrease standard deviation shows within this indicator that speed varies greatly on indicates effective speed the street, leading to less management. predictability and higher crash risk.

th th Median speed: The 85 percentile speed: The 95 percentile speed: speed of the 50th speed of the 85th percentile The speed of the 95th percentile driver. This driver. Cities should not collect percentile driver. This number can be used to and report on 85th percentile number can be used as understand the speed speeds in isolation—95th an estimate of the fastest of typical drivers, rather percentile speeds and median speed that a typical user than the fastest drivers. speeds help round out the will encounter, and can be picture of dangerous speeds used as a measure of how on the street. well speeds have been Photo: Cyrus Tetteh City of Detroit-CCSD78 managed.

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CHANGES IN FATAL AND SERIOUS CRASHES CHANGES IN SPEEDING OPPORTUNITY x Streets with a history of multiple people killed they occurred, and what caused them) to Speeding occurs where drivers are Speeding opportunity can be modeled as or seriously injured in traffic crashes over five both prioritize projects and make design comfortable exceeding a safe speed because the number of motor vehicles arriving at a years may have underlying safety risks that are and engineering decisions. of the design of the street, and when they point no other vehicles have passed for a likely to recur. Examining crash history by travel have an opportunity to speed because there set time, such as five seconds. For example, Short-term crash data can be unreliable, mode provides a basis for understanding the are no other cars ahead. Streets with excess for signalized intersections, drivers have a especially for the most serious crashes. existing risks on the street. Even when “speed” motor vehicle capacity at either peak or non- speeding opportunity if they arrive at the Using three to five “before” years of crash or “speeding” is not listed on a crash report, peak times tend to provide opportunities to intersection on a green signal at least five data and evaluating how the “after” speed may be an underlying factor; speeding is speed. Similarly, multilane streets as well seconds after the previous vehicle. condition differs will help practitioners underreported in US traffic crashes, and speed as signalized streets with long green phases draw conclusions about the effectiveness Speeding opportunity can also be discussed at crash is not always available.79 Further, and/or high-speed progressions provide, by of a safety project. Combining severe as a daily vehicle volume: a street with several fatal and serious injury crashes involving definition, more opportunities to speed than injury with fatality data is another way to hundred opportunities to speed per day pedestrians, bicycles, and left turning vehicles a one-lane street. improve the reliability of crash analysis at will produce far fewer injuries than one with often can be addressed in part through speed the project level. Analyzing speeding opportunities on a corridor several thousand opportunities to speed reduction. Cities should use data about fatal can provide planners with information about per day, assuming each vehicle has a similar and serious injury crashes (when and where the best speed mitigation strategies, for potential for conflicts. Speed management example through signal operations changes, projects should aim to greatly reduce the limiting the number of motor vehicle lanes, or number of speeding opportunities in a given DENVER repurposing motor vehicle lanes to other uses. street, corridor, or zone.

DETROIT

Photo: Google

Map: Denver Vision Zero Data Dashboard Photo: Lauren Ann Davies

A five-year history of fatal and serious injury crashes can help practitioners understand the risks already present on a street. Denver uses a dashboard to track and display crashes on the street network. In addition to understanding where crashes happen, cities should also look into why they are happening, and use that to make decisions about street design and project prioritization.

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CHANGES IN CONFLICT COUNTS Section 3 Endnotes Conflict counts are a surrogate measure of (if no evasive action is taken) or post- safety. They should be prioritized as part of encroachment time (how soon after one 53. Jurewicz, C., Sobhani, A., Woolley, J., Dutschke, J., 69. National Highway Traffic Safety Administration a Safe Speed Study when changes to street participant passes a specific point does the Corben, B., (2016). Exploration of vehicle impact (2016). System Analysis of Automated Speed speed – injury severity relationships for application Enforcement Implementation. Retrieved from: design or activity levels mean that simpler other participant go through it). in safer road design. Transportation Research https://www.nhtsa.gov/sites/nhtsa.dot.gov/ measures, such as crash history, will not Procedia 14, 4247-4256. files/812257_systemanalysisase.pdf. Conflicts per entry (conflict counts divided sufficiently approximate risks on the street. 54. Tefft, B.C. (2011). Impact Speed and a Pedestrian’s 70. Centers for Disease Control and Prevention. by the vehicle and person-entries) into an Risk of Severe Injury or Death. AAA Foundation Motor Vehicle Safety: Automated Speed-Camera Conflict counts are completed by observing the intersection provide the likelihood that for Traffic Safety. Retrieved from: https:// Enforcement. Retrieved from: https://www.cdc. number of times per day or per hour that two each person using the street at a particular aaafoundation.org/impactspeed-pedestrians-risk- gov/motorvehiclesafety/calculator/factsheet/ severe-injurydeath/. speed.html. people or vehicles are on a collision course and location for a particular movement will be must take evasive action to prevent a crash. involved in a conflict.80 55. Jurewicz, C., Sobhani, A., Woolley, J., Dutschke, J., 71. New York City Department of Transportation Corben, B., (2016). Exploration of vehicle impact (2018). Automated Speed Enforcement Program Common conflict classification methods speed – injury severity relationships for application Report 2014-2017. Retrieved from: http://www. for urban streets include time-to-collision in safer road design. Transportation Research nyc.gov/html/dot/downloads/pdf/speed- Procedia 14, 4247-4256. camera-report-june2018.pdf.

56. Federal Highway Administration. Functional 72. Ibid. Classification Concepts, Criteria and Procedures. Retrieved from: https://www.fhwa.dot.gov/ 73. Ibid. planning/processes/statewide/related/highway_ 74. www.metouhey.com ADDITIONAL DATA functional_classifications/section03.cfm. 75. Transportation Alternatives. Our Story. . . . Several other street characteristics are 57. Federal Highway Administration (2012). Methods Retrieved from: https://www.transalt.org/ and Practices for Setting Speed Limits. Retrieved routinely considered in speed limit studies, and ourstory?rq=speed%20limit. from: https://safety.fhwa.dot.gov/speedmgt/ref_ may provide a starting point for determining mats/fhwasa12004/fhwasa12004.pdf (page 10). 76. Note that a simple before-after comparison may appropriate design and engineering measures not show the true effect of a speed management 58. Ibid (page 26). for speed management: project. The comparison does not control for 59. National Safety Council. Motor Vehicle Safety other factors that may have affected the number Issues: Speeding. Retrieved from: https:// of crashes or speeds. It is important to include injuryfacts.nsc.org/motor-vehicle/motor-vehicle- an appropriate control group to control for these safety-issues/speeding/. factors.

60. National Highway Traffic Safety Administration. 77. Federal Highway Administration (1998). Fatality Analysis and Reporting System. Retrieved Synthesis of Safety Research Related to Speed from: https://www.nhtsa.gov/es/research-data/ and Speed Management. Retrieved from: https:// fatality-analysis-reporting-system-fars. www.fhwa.dot.gov/publications/research/ safety/98154/speed.cfm. 61. Federal Highway Administration (2018). Self- Enforcing Roadways: A Guidance Report. 78. Seattle Department of Transportation (2017). Publication No. FHWA-HRT-17-098. Retrieved from: Rainier Avenue South Safety Corridor: Rainier https://www.fhwa.dot.gov/publications/research/ Pilot Project Evaluation. Retrieved from: https:// safety/17098/17098.pdf. www.seattle.gov/Documents/Departments/ SDOT/MaintenanceProgram/RainierAveS_ 62. These treatments are appropriate for some major BeforeAfter.pdf (page 13). streets, but not large multi-lane arterials. 79. Permission to use photo by K. Shabu Supervising 63. Furth, P. G., Halawani, A. T. M., Li, J., Hu, W. (Jake), Photographer. & Cesme, B. (2018). Using Traffic Signal Control to Limit Speeding Opportunities on Bidirectional 80. Cherry, Christopher et al. (November 2018). Urban Arterials. Transportation Research Record, Completing the Picture of Traffic Injuries: 2672(18), 107–116. Retrieved from: https://doi. Understanding Data Needs and Opportunities org /10.1177/0361198118790638. for Road Safety. Collaborative Sciences Center for Road Safety. Retrieved from: https:// 64. Ibid. www.roadsafety.unc.edu/wp-content/ uploads/2018/11/CSCRS_R4_FinalReport.pdf. 65. Karim, Dewan Masud (2015). Narrower Lanes, Safer Streets. Accepted Paper for CITE Conference. 81. More information on the major conflict techniques can be found at Kraay, J..H., et al. 66. Photo: Bruce Englehardt/Seattle Transit Blog (2013). Manual conflict observation technique DOCTOR. Road Safety for All. https://www.ictct. Street width Traffic calming elements Surface quality, 67. Stanford Open Policing Project. Retrieved from: net/wp-content/uploads/SMoS_Library/LIB_ https://openpolicing.stanford.edu/. roadside conditions, Kraay_et_al_2013.pdf. and sightlines 68. Ibid.

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Photo: NACTO

4 Checklists Analyzing Existing Conditions & Using the Risk Matrix

These checklists are a starting point for analyzing how dense conflicts are on a given street and how active that street is, in order to determine a safe speed limit for a street.

To support quantitative analysis, cities can determine specific thresholds (e.g., What does “high pedestrian volume” mean in your city?) based on local conditions. This guidance avoids determining thresholds so as not to be overly prescriptive. Checklists NACTO City Limits City Limits NACTO Checklists

CONFLICT DENSITY ANALYSIS CHECKLIST

IF the street has... Sample Conflict Density Metrics START: IF any of these apply to the street... IF the street has... No “through” or “T” There are many metrics that a city can use intersections (signalized to measure a street’s conflict levels. The or unsignalized), major list below provides a starting point. Cities driveways, or other No sidewalks 1-3 “through” or “T” can set quantitative thresholds based on intersections (signalized crossing points per ¼ mile local conditions. AND or unsignalized), major OR driveways, or other Pedestrian Pedestrians AND crossing points per ¼ mile crossing volume walking in the Curbside loading/parking Bicycle traffic in the traffic per day or hour street per hour lane and sidewalk, or a lane, even where marked or Curbside loading/parking USDG-compliant sidewalk signed (e.g., sharrows) lane and sidewalk, or a OR USDG-compliant sidewalk AND Left turn volume Midblock or AND per day or hour uncontrolled- EITHER: intersection Sidewalks directly Passengers exiting crossings per adjacent to moving traffic parked or loading vehicles Motor vehicle lane hour per ¼ mile A marked bike lane or are not directly in general blockage or bike- OR better, if designated traffic lanes bike route lane blockage AND percent per hour ≥ 3 “through” or “T” OR EITHER: intersections (signalized A full sidewalk with or unsignalized), major permissible bike use, if not driveways, or other crossing a designated bike route Protected bike lane, points per ¼ mile shared use path, or USDG consistent sidewalk, if RESULTS FOR: Conflict Density Analysis designated bike route OR Based on the conflict density Full sidewalk with legally analysis, the street has: permissible bike use, if not designated a bike lane HIGH CONFLICT DENSITY

THEN the street has: IF NOT, proceed... THEN the street has: IF NOT, proceed... THEN the street has: MODERATE CONFLICT DENSITY

HIGH CONFLICT MODERATE CONFLICT LOW CONFLICT DENSITY DENSITY DENSITY LOW CONFLICT DENSITY

PROCEED to the Activity Analysis. PROCEED to the Activity Analysis. PROCEED to the Activity Analysis.

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ACTIVITY LEVEL ANALYSIS CHECKLIST

START: IF the street is any of the following... IF the street is a... IF the street is a... Sample Activity Level Metrics There are many metrics that a city can use to measure a street’s activity levels. The list below provides a starting point. Cities can Downtown / Central Moderate density Low density industrial use land use metrics as an alternative in the Business District residential or or residential street absence of the volumes below. Cities can set street commercial street quantitative high, medium, and low activity OR OR thresholds based on local conditions. Street with light retail Retail corridor activity Pedestrian Scheduled transit sidewalk volume stops per hour OR per day or hour OR Social and public Bicycle volume High density Mixed use corridor space use volume per day or hour per day or hour residential or commercial street Parking or curbside Crash volumes loading maneuvers by mode per hour

THEN the street has: IF NOT, proceed... THEN the street has: IF NOT, proceed... THEN the street has: RESULTS FOR: Activity Level Analysis

HIGH ACTIVITY MODERATE ACTIVITY LOW ACTIVITY Based on the activity level analysis, the street has:

HIGH ACTIVITY

MODERATE ACTIVITY

LOW ACTIVITY PROCEED to the Risk Matrix. PROCEED to the Risk Matrix to determine PROCEED to the Risk Matrix. the correct speed limit for the street.

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APPLYING THE CONFLICT & ACTIVITY LEVEL ANALYSIS + TO THE RISK MATRIX

CONTINUE Based on the Conflict FINISH Density Analysis, the Based on the analyses, the major street’s speed limit should be: street has...

Based on the Activity CONTINUE HIGH MODERATE LOW CONFLICT Level Analysis, the CONFLICT CONFLICT DENSITY DENSITY street has... 20 25 MPH MPH 20 20 25 MPH MPH MPH

HIGH ACTIVITY

20 25 30 MPH MPH MPH 30 35 MPH MPH MODERATE ACTIVITY

25 25 35 MPH MPH MPH

LOW ACTIVITY

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