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2017 N A T I O N A L C O O P E R A T I V E H I G H W A Y R E S E A R C H P R O G R A M NCHRP RESEARCH REPORT 841 Development of Crash Modification Factors for Uncontrolled Pedestrian Crossing Treatments Charles Zegeer Raghavan Srinivasan Bo Lan Daniel Carter Sarah Smith Carl Sundstrom Nathan J. Thirsk HigHway Safety ReSeaRcH centeRâUniveRSity of noRtH caRolina Chapel Hill, NC Craig Lyon Bhagwant Persaud PeRSaUd and lyon, inc. Toronto, ON, Canada John Zegeer KittelSon and aSSociateS, inc. Fort Lauderdale, FL Erin Ferguson KittelSon and aSSociateS, inc. Oakland, CA Ron Van Houten centeR foR edUcation and ReSeaRcH in Safety Kalamazoo, MI Subscriber Categories Highwaysâ â¢â Designâ â¢â OperationsâandâTrafficâManagement Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed research is the most effective way to solve many problems facing highway administrators and engineers. Often, highway problems are of local interest and can best be studied by highway departments individually or in cooperation with their state universities and others. However, the accelerating growth of highway transportation results in increasingly complex problems of wide inter- est to highway authorities. These problems are best studied through a coordinated program of cooperative research. Recognizing this need, the leadership of the American Association of State Highway and Transportation Officials (AASHTO) in 1962 ini- tiated an objective national highway research program using modern scientific techniquesâthe National Cooperative Highway Research Program (NCHRP). NCHRP is supported on a continuing basis by funds from participating member states of AASHTO and receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board (TRB) of the National Academies of Sciences, Engineering, and Medicine was requested by AASHTO to administer the research program because of TRBâs recognized objectivity and understanding of modern research practices. TRB is uniquely suited for this purpose for many reasons: TRB maintains an extensive com- mittee structure from which authorities on any highway transportation subject may be drawn; TRB possesses avenues of communications and cooperation with federal, state, and local governmental agencies, univer- sities, and industry; TRBâs relationship to the Academies is an insurance of objectivity; and TRB maintains a full-time staff of specialists in high- way transportation matters to bring the findings of research directly to those in a position to use them. The program is developed on the basis of research needs identified by chief administrators and other staff of the highway and transporta- tion departments and by committees of AASHTO. Topics of the highest merit are selected by the AASHTO Standing Committee on Research (SCOR), and each year SCORâs recommendations are proposed to the AASHTO Board of Directors and the Academies. Research projects to address these topics are defined by NCHRP, and qualified research agencies are selected from submitted proposals. Administration and surveillance of research contracts are the responsibilities of the Acad- emies and TRB. The needs for highway research are many, and NCHRP can make significant contributions to solving highway transportation problems of mutual concern to many responsible groups. The program, however, is intended to complement, rather than to substitute for or duplicate, other highway research programs. Published research reports of the NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM are available from Transportation Research Board Business Office 500 Fifth Street, NW Washington, DC 20001 and can be ordered through the Internet by going to http://www.national-academies.org and then searching for TRB Printed in the United States of America NCHRP RESEARCH REPORT 841 Project 17-56 ISSN 0077-5614 ISBN 978-0-309-44626-6 Library of Congress Control Number 2017934546 Â© 2017 National Academy of Sciences. All rights reserved. COPYRIGHT INFORMATION Authors herein are responsible for the authenticity of their materials and for obtaining written permissions from publishers or persons who own the copyright to any previously published or copyrighted material used herein. Cooperative Research Programs (CRP) grants permission to reproduce material in this publication for classroom and not-for-profit purposes. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, FAA, FHWA, FMCSA, FRA, FTA, Office of the Assistant Secretary for Research and Technology, PHMSA, or TDC endorsement of a particular product, method, or practice. It is expected that those reproducing the material in this document for educational and not-for-profit uses will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from CRP. NOTICE The research report was reviewed by the technical panel and accepted for publication according to procedures established and overseen by the Transportation Research Board and approved by the National Academies of Sciences, Engineering, and Medicine. The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research and are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; or the program sponsors. The Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; and the sponsors of the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturersâ names appear herein solely because they are considered essential to the object of the report.
The National Academy of Sciences was established in 1863 by an Act of Congress, signed by President Lincoln, as a private, non- governmental institution to advise the nation on issues related to science and technology. Members are elected by their peers for outstanding contributions to research. Dr. Marcia McNutt is president. The National Academy of Engineering was established in 1964 under the charter of the National Academy of Sciences to bring the practices of engineering to advising the nation. Members are elected by their peers for extraordinary contributions to engineering. Dr. C. D. Mote, Jr., is president. The National Academy of Medicine (formerly the Institute of Medicine) was established in 1970 under the charter of the National Academy of Sciences to advise the nation on medical and health issues. Members are elected by their peers for distinguished contributions to medicine and health. Dr. Victor J. Dzau is president. The three Academies work together as the National Academies of Sciences, Engineering, and Medicine to provide independent, objective analysis and advice to the nation and conduct other activities to solve complex problems and inform public policy decisions. The Academies also encourage education and research, recognize outstanding contributions to knowledge, and increase public understanding in matters of science, engineering, and medicine. Learn more about the National Academies of Sciences, Engineering, and Medicine at www.national-academies.org. The Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. The mission of the Transportation Research Board is to increase the benefits that transportation contributes to society by providing leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisciplinary, and multimodal. The Boardâs varied committees, task forces, and panels annually engage about 7,000 engineers, scientists, and other transportation researchers and practitioners from the public and private sectors and academia, all of whom contribute their expertise in the public interest. The program is supported by state transportation departments, federal agencies including the component administrations of the U.S. Department of Transportation, and other organizations and individuals interested in the development of transportation. Learn more about the Transportation Research Board at www.TRB.org.
C O O P E R A T I V E R E S E A R C H P R O G R A M S AUTHOR ACKNOWLEDGMENTS The research report authors appreciate the assistance of all of the city officials throughout the United States who were contacted regarding information on the status of pedestrian treatments that have been implemented. The authors are particularly grateful for the support and cooperation of officials from the 14 cities where treatments were selected. This includes officials from Arlington and Alexandria, VA; Cambridge, MA; Charlotte, NC; Chicago, IL; Milwaukee, WI; New York, NY; Eugene and Portland, OR; Miami and St. Petersburg, FL; and Phoenix, Scottsdale, and Tucson, AZ. Also, officials from the respective state DOTs were very helpful in providing crash data for the sites within their cities. This research could not have been conducted without assistance from those city and state DOT officials. CRP STAFF FOR NCHRP RESEARCH REPORT 841 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Gary A. Jenkins, Senior Program Assistant Eileen P. Delaney, Director of Publications Ellen M. Chafee, Senior Editor NCHRP PROJECT 17-56 PANEL Field of TrafficâArea of Safety Jarrod Stanley, Kentucky Transportation Cabinet, Frankfort, KY (Chair) Brian W. Alconcel, California DOT, Sacramento, CA Daniel M. Dulaski, Northeastern University, Boston, MA Alan S. El-Urfali, Florida DOT, Tallahassee, FL Joe Fish, Toole Design Group, Denver, CO Melanie J. Hughes, VA Department for the Blind and Vision Impaired, Fairfax, VA Greg Scott Lippincott, Washington State DOT, Olympia, WA Carrie L. Simpson, North Carolina DOT, Raleigh, NC Scott J. Windley, U.S. Access Board, Washington, DC Tamara Redmon, FHWA Liaison Bernardo Kleiner, TRB Liaison
This report quantifies the safety benefits of four types of pedestrian crossing treatmentsâ rectangular rapid flashing beacons, pedestrian hybrid beacons, pedestrian refuge islands, and advanced YIELD or STOP markings and signsâand presents a recommended crash modification factor (CMF) for each treatment type. This information, which is suitable for inclusion in the AASHTO Highway Safety Manual, FHWAâs CMF Clearinghouse, and other guidance, will be valuable to transportation agencies in choosing the appropriate crossing treatment for uncontrolled pedestrian crossings. There is considerable uncertainty surrounding the use of pedestrian crossing treatments at uncontrolled crossing locations. Research shows that marking crosswalks without making additional improvements is associated with higher pedestrian crash rates under certain road- way configurations and operating characteristics, such as on high-volume multi-lane roads (Zegeer, C.V., Stewart, J.R., Huang, H.H., and Lagerwey, P.A. Safety Effects of Marked vs. Unmarked Crosswalks at Uncontrolled Locations, Federal Highway Administration, 2001). However, failing to provide crossing opportunities, installing inappropriate roadway treat- ments, or over-improving an area are all undesirable solutions. Where a crosswalk alone might lead to increased pedestrian crashes, Zegeer et al. recommend enhanced crossing treatments, noting that âpedestrian crossing problems and needs should be routinely identi- fied, and appropriate solutions should be selected to improve pedestrian safety and access.â While several studies have examined pedestrian safety at uncontrolled crossing locations, robust CMFs are generally lacking. Under NCHRP Project 17-56, the University of North Carolina Highway Safety Research Center (HSRC) was asked to (1) quantify the relationships between pedestrian safety and crossing treatments at uncontrolled locations (excluding roundabouts) and (2) develop CMFs by crash type and severity for (a) unsignalized pedestrian crosswalk signs and pavement mark- ings, including advanced YIELD markings; (b) pedestrian hybrid beacons; (c) rectangular rapid flashing beacons; (d) pedestrian refuge areas; (e) curb extensions; (f ) in-pavement warning lights; and/or (g) high-visibility crosswalk marking patterns. The HSRC conducted an extensive literature review, collected and evaluated data for numerous uncontrolled pedestrian crossing locations in a number of cities, and narrowed the list of crossing treatments for full evaluation to four: rectangular rapid flashing beacons, pedestrian hybrid beacons, pedestrian refuge islands, and advanced YIELD or STOP mark- ings and signs. The research team analyzed before and after crash data and developed crash prediction models for those four treatment types at nearly 1,000 locations in 14 cities and developed CMFs for each treatment. To facilitate implementation of the research results, the findings of this research are appropriate for inclusion in the AASHTO Highway Safety Manual, the Federal Highway Administrationâs CMF Clearinghouse, design guidance for uncontrolled pedestrian crossings, and other documents. F O R E W O R D ByâLoriâL.âSundstrom StaffâOfficer TransportationâResearchâBoard
1â Summary 4 Chapter 1â ProjectâOverview 6 Chapter 2â LiteratureâReview 6 Unsignalized Pedestrian Crosswalk Signs and Pavement Markings, Including Advanced YIELD or STOP Markings and Signs 7 High-Visibility Crosswalk Marking Patterns 8 Pedestrian Hybrid Beacons 9 Rectangular Rapid Flashing Beacons 10 In-Pavement Warning Lights 10 Pedestrian Refuge Islands 11 Curb Extensions 12 Raised Pedestrian Crossings 13 Chapter 3â DataâCollection 13 Site Identification 14 Compiling Site Data 15 Summary of Site Characteristics 19 Collection of Pedestrian Count Data 22 Collection of Crash and Average Annual Daily Traffic Data 24 Chapter 4â DataâAnalysis 24 Crash Modification Factor Development for Pedestrian Treatments 25 Before-After Evaluation 30 Crash Modification Factor Estimation from Cross-Sectional Regression Analysis 45 Comparison of Before-After and Cross-Sectional Study Results 46 Consolidation of Analysis Results 48 Chapter 5â SummaryâandâConclusions 48 Study Objectives and Results 48 Data Limitations and Recommendations 50 Criteria for Treatment Installation 53 Chapter 6â âIncorporationâofâStudyâResultsâ intoâNationalâGuidelines 53 Highway Safety Manual 54 Crash Modification Factor Clearinghouse 54 Proven Safety Countermeasures Website 54 NCHRP Report 600: Human Factors Guidelines for Road Systems, Second Edition 55 Manual on Uniform Traffic Control Devices 55 Design Guidance for Uncontrolled Pedestrian Crossings 56â References C O N T E N T S
60 Appendix Aâ SelectedâTreatmentâTypesâforâEvaluation 63 Appendix Bâ âTreatmentâandâComparisonâSiteâExamplesâ ofâPedestrianâCountâSummaries 72 Appendix Câ âAnalysisâofâCharlotteâPedestrianâVolumesâ toâDetermineâPedestrianâCountingâProcedureâ forâNCHRPâProjectâ17-56 77 Appendix Dâ âAnalysisâofâCharlotteâPedestrianâVolumesâ toâDetermineâMethodâforâAdjustingâ PedestrianâVolumeâCounts 81 Appendix Eâ âSafetyâPerformanceâFunctionsâforâtheâ Before-AfterâEvaluation 85 Appendix Fâ âSelectionâandâAssessmentâofâModelâFormâ forâCross-SectionalâModels 88 Appendix Gâ âNCHRPâProjectâ17-56âDatabaseâCreationâ andâDataâEntryâMethodologyâNotes 96 Appendix Hâ âEffectsâofâPedestrianâTreatmentsâ atâUnsignalizedâCrossings:â AâSummaryâofâAvailableâResearch