NCDOT Project 2011-08 FHWA/NC/2011-08 August 2013 Speed and Safety in North Carolina Libby Thomas, et al. Highway Safety Research Center University of North Carolina - Chapel Hill Final Report 2011-08 Speed and Safety in North Carolina Libby Thomas Phone: 919-962-7802; Email: [email protected] Raghavan Srinivasan Phone: 919-962-7418; Email: [email protected] Bo Lan Phone: 919-962-0465; Email: [email protected] William Hunter Email: [email protected] Carol Martell Phone: 919- 962-8713; Email: [email protected] Eric Rodgman: Phone: 919- 962-8709; Email: [email protected] Performing Agency: University of North Carolina Highway Safety Research Center 730 Martin Luther King Jr Blvd Chapel Hill, NC 27599-3430 Submitted to North Carolina Department of Transportation August 23, 2013 Technical Report Documentation Page 1. Report No. 2. Government Accession No. 3. Recipient’s Catalog No. FHWA/NC/2011‐08 4. Title and Subtitle 5. Report Date August 23, 2013 Speed and Safety in North Carolina 6. Performing Organization Code 7. Author(s) 8. Performing Organization Report No. Libby Thomas, Raghavan Srinivasan, Bo Lan, William Hunter, Carol Martell, and Eric Rodgman 9. Performing Organization Name and Address 10. Work Unit No. (TRAIS) Highway Safety Research Center University of North Carolina, CB # 3430 11. Contract or Grant No. 730 Martin Luther King Jr Blvd Chapel Hill, NC 27599‐3430 12. Sponsoring Agency Name and Address 13. Type of Report and Period Covered North Carolina Department of Transportation Final Report Research and Development August 16, 2010 – April 30, 2013 1549 Mail Service Center 14. Sponsoring Agency Code Raleigh, North Carolina 27699‐1549 2011-08 Supplementary Notes: 16. Abstract With nearly 5000 people losing their lives and many more injured in North Carolina speeding‐related crashes over the past decade, more concerted and cooperative action is needed to address speeding as a major safety problem in the State. The project team was tasked with conducting a literature review to identify best practices with regard to speed management, to characterize the problem of speeding in the State, and to come up with recommendations that the State might implement to significantly bring down the numbers of killed and seriously injured due to inappropriate speeds. In addition, a Symposium and workshop were organized to identify effective strategies and policies being used around the world that may help to reduce speeding‐related safety problems if implemented in North Carolina. Ultimately, 21 different best practice and evidence‐based countermeasure recommendations were developed with potential to reduce speeding and severe crashes. The background information and recommendations developed are described in this report, and the recommendations are also summarized in a separate document, North Carolina Speed Management: Recommendations for Action. Several promising innovative strategies were included among the recommendations. One of the recommendations was to develop approaches to prioritize routes for speed limit and safety review. This report also describes several methods developed, in a second phase of the project, to screen the network to identify and prioritize corridors that may have speeding‐related crash problems that could benefit from further problem diagnosis and treatment. 17. Key Words 18. Distribution Statement Speed management, traffic speed and safety, speeding‐related crashes, network screening, fatal and injury crashes, countermeasures 19. Security Classif. (of this report) 20. Security Classif. (of this page) 21. No. of Pages 22. Price Unclassified Unclassified Form DOT F 1700.7 (8‐72) Reproduction of completed page authorized DISCLAIMER The contents of this report reflect the views of the author(s) and not necessarily the views of the University. The author(s) are responsible for the facts and the accuracy of the data presented herein. The contents do not necessarily reflect the official views or policies of either the North Carolina Department of Transportation or the Federal Highway Administration at the time of publication. This report does not constitute a standard, specification, or regulation. ii ACKNOWLEDGEMENTS This project had two phases and many parts and there are many people who could be acknowledged for their contributions. We thank the North Carolina Department of Transportation (NCDOT) for funding this effort. We thank the following individuals for serving on the project Steering and Implementation Committee: Brian Mayhew, P.E. (Chair) Dwayne Alligood, P.E. Mrinmay Biswas, Ph.D. A. C. Braam, P.E. Brad Hibbs, P.E. Terry M. Hopkins, P.E. Kevin Lacy, P.E., C.P.M. Don Nail Anthony Wyatt, P.E., PTOE We also thank Ernest Morrison for serving as the NCDOT research office liaison for this project. Brian Mayhew and Kevin Lacy provided guidance and vision throughout this study. Many other individuals at NCDOT, including with the Governor’s Highway Safety Program, assisted with Symposium and workshop planning, provided data, answered queries or participated in telephone interview or stakeholder meetings. The project team also acknowledges the contributions of many other North Carolina agency representatives, including the North Carolina Department of Justice, the North Carolina Legislative Child Fatality Task Force, North Carolina Department of Health and Human Services - Injury and Violence Prevention Branch, North Carolina District Attorneys, North Carolina State Highway Patrol, and local law enforcement agencies. In addition, the National Highway Traffic Safety Administration was represented. We also acknowledge the speed management experts, Dr. Letty Aarts, SWOV, the Road Safety Research Institute of the Netherlands; Dr. Bruce Corben, Monash University Accident Research Centre, Melbourne, Australia; Dr. David Shinar, Ben Gurion University of the Negev, Beer Sheva, Israel; Dr. Jim Hedlund, Principal, Highway Safety North; and Nancy Lefler, VHB; and Mr. Path Stith, journalist, for sharing their expertise with North Carolina. Other HSRC staff also assisted with the Symposium and other aspects of this project including Forrest Council, who chaired the workshop and participated in the symposium. We also acknowledge the assistance of Patty Harrison, Jonathon Weisenfeld, Daniel Carter, Graham Russell, Jean Justice, and former HSRC staff including Katy Jones and Jonathon Gerler. iii EXECUTIVE SUMMARY With nearly 5000 people losing their lives in North Carolina speeding-related crashes over the past decade, more concerted and cooperative action is needed to address speeding as a major safety problem in the State. Although there have been reductions in the numbers of people killed or seriously injured due to speeding in recent years, the long-term trend of fatalities associated with speeding continues at between 30 and 40 percent, which is higher than the fatalities associated with alcohol use or lack of restraint use. Since speeding is so integrally-related to the severity of injuries received in crashes, the State is seeking comprehensive methods to improve compliance with speed limits and reduce fatal and injury crashes associated with exceeding limits or exceeding a safe speed for conditions. The project team was tasked with conducting a literature review to identify best practices with regard to speed management, to characterize the problem of speeding in the State, and to come up with recommendations that the State could implement to significantly bring down the numbers of killed and seriously injured. To help with the latter effort, a Speed Symposium was held in October of 2011, featuring international experts in speed management to report on successful methods being used to manage speed and reduce fatalities and injuries. The Symposium was followed by a North Carolina- focused workshop that included North Carolina road safety stakeholder agency representatives and the speed management experts. This group of experts identified North Carolina-specific issues and recommendations for improving speed management in the State. Ultimately, 22 different best practice and evidence-based countermeasure recommendations were developed with potential to reduce speeding and severe crashes. The recommendations are described in this report, and are also summarized in a separate document, North Carolina Speed Management: Recommendations for Action. Several promising innovative strategies were included among the recommendations. There are many miles of roadways in North Carolina, and the speeding crash problem is fairly widely dispersed across all types of roads, particularly in rural areas. One of the recommendations was to come up with methods to prioritize roads for speed limit and safety review. The Network Screening section and Appendices III and IV describe several methods developed to screen the network to identify corridors that may have speeding-related crash and injury problems. Of the three primary methods discussed, the first two approaches made use of the state of the art empirical Bayes method to screen six different types of roadways for crashes associated with speeding or with more severe crashes. (Other crash types and combinations of speeding with particular crash types were also tried.) Corridors were also screened based on proportions of crashes that were speeding-related and/or severe compared to total crashes. Within each method, there are a number of possible ways of ranking the results. One method we used was to combine results from screening based on speeding and screening based on