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TRANSPORTAT ION RESEARCH BOARD WASHINGTON, D.C. 2010 www.TRB.org 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 REPORT 665 Subscriber Categories Safety and Human Factors Identification of Vehicular Impact Conditions Associated with Serious Ran-off-Road Crashes King K. Mak MAK & ASSOCIATES San Antonio, TX Dean L. Sicking Francisco Daniel Benicio de Albuquerque MIDWEST ROADSIDE SAFETY FACILITY Lincoln, NE Brian A. Coon CITY ENGINEERâS OFFICE Wichita, KS 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 provides the most effective approach to the solution of 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 develops increasingly complex problems of wide interest to highway authorities. These problems are best studied through a coordinated program of cooperative research. In recognition of these needs, the highway administrators of the American Association of State Highway and Transportation Officials initiated in 1962 an objective national highway research program employing modern scientific techniques. This program is supported on a continuing basis by funds from participating member states of the Association and it receives the full cooperation and support of the Federal Highway Administration, United States Department of Transportation. The Transportation Research Board of the National Academies was requested by the Association to administer the research program because of the Boardâs recognized objectivity and understanding of modern research practices. The Board is uniquely suited for this purpose as it maintains an extensive committee structure from which authorities on any highway transportation subject may be drawn; it possesses avenues of communications and cooperation with federal, state and local governmental agencies, universities, and industry; its relationship to the National Research Council is an insurance of objectivity; it maintains a full-time research correlation staff of specialists in highway transportation matters to bring the findings of research directly to those who are in a position to use them. The program is developed on the basis of research needs identified by chief administrators of the highway and transportation departments and by committees of AASHTO. Each year, specific areas of research needs to be included in the program are proposed to the National Research Council and the Board by the American Association of State Highway and Transportation Officials. Research projects to fulfill these needs are defined by the Board, and qualified research agencies are selected from those that have submitted proposals. Administration and surveillance of research contracts are the responsibilities of the National Research Council and the Transportation Research Board. The needs for highway research are many, and the National Cooperative Highway Research Program can make significant contributions to the solution of 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 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 at: http://www.national-academies.org/trb/bookstore Printed in the United States of America NCHRP REPORT 665 Project 17-22 ISSN 0077-5614 ISBN 978-0-309-15507-6 Library of Congress Control Number 2010936963 © 2010 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, FTA, or Transit Development Corporation 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 project that is the subject of this report was a part of the National Cooperative Highway Research Program, conducted by the Transportation Research Board with the approval of the Governing Board of the National Research Council. The members of the technical panel selected to monitor this project and to review this report were chosen for their special competencies and with regard for appropriate balance. The 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 Governing Board of the National Research Council. 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 Research Council, or the program sponsors. The Transportation Research Board of the National Academies, the National Research Council, 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.
CRP STAFF FOR NCHRP REPORT 665 Christopher W. Jenks, Director, Cooperative Research Programs Crawford F. Jencks, Deputy Director, Cooperative Research Programs Charles W. Niessner, Senior Program Officer Emily R. Greenwood, Senior Program Assistant Eileen P. Delaney, Director of Publications Natalie Barnes, Editor NCHRP PROJECT 17-22 PANEL Field of TrafficâArea of Safety Richard B. Albin, Federal Highway Administration, Lakewood, CO (Chair) Jonathan Becker, South Dakota DOT, Pierre, SD Don J. Gripne, Trinity Highway Products, LLC, Olympia, WA Douglas E. McClure, South Carolina DOT, Columbia, SC Catherine McCullough, National Highway Traffic Safety Administration, Washington, DC Ronald J. Seitz, Kansas DOT, Topeka, KS Manu G. Shah, Hanover, MD Harry W. Taylor, Jr., Taylor Consulting, Washington, DC Richard Pain, TRB Liaison AUTHOR ACKNOWLEDGMENTS The authors wish to acknowledge several sources that made a contribution to this project: (1) the Trans- portation Research Board of the National Academies for managing this project and (2) the NCHRP Proj- ect 17-22 panel for its guidance. A special thanks is also given to the following individuals who made a contribution to the completion of this research project. Midwest Roadside Safety Facility John R. Rohde, Ph.D., P.E., Associate Professor John D. Reid, Ph.D., Professor Ronald K. Faller, Ph.D., P.E., Research Assistant Professor Karla A. Lechtenberg, M.S.M.E., E.I.T., Research Associate Engineer Robert W. Bielenberg, M.S.M.E., E.I.T., Research Associate Engineer Scott K. Rosenbaugh, M.S.C.E., E.I.T., Research Associate Engineer Undergraduate and Graduate Research Assistants Transportation Research Board NCHRP Project 17-22 Panel Members 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
This report quantifies the characteristics of ran-off-road crashes and identifies appropri- ate impact conditions for use in full-scale crash testing. Many of the decisions related to design guidelines and policies can benefit from better information on the impact conditions of ran-off-road crashes. The report will be of particular interest to personnel responsible for the design of roadside safety features. The primary goal of roadside design is to limit the number of serious injuries and fatali- ties associated with ran-off-road crashes. Roadside geometrics and safety features have a strong influence on the frequency and severity of crashes. To design optimum roadside geo- metrics and to determine which roadside safety features are appropriate, it is imperative to identify impact characteristics associated with serious injury and fatal crashes. This infor- mation has a direct bearing on safety evaluation criteria used to assess the performance of roadside safety features. However, the impact speeds, angles, and orientations used in the current testing procedures are selected to represent a practical worst-case situation. It is unclear to what degree this practical worst-case situation represents real-world conditions. Consequently, it is important to have definitive data on whether there are real relationships between the selected test impact conditions and actual crashes involving serious injuries and fatalities. Crash data will be useful in refining guidelines for roadside safety countermeasures and calibrating roadside safety models [e.g., Roadside Safety Analysis Program (RSAP)] and crash and vehicle dynamics simulation models. It will also be helpful in focusing designers' attention on the roadside features that are involved in the greatest number of serious injury and fatal crashes. Crash data will help designers spend safety dollars on improvements that will have the greatest likelihood of reducing serious injuries and fatalities. Under NCHRP Project 17-22, âIdentification of Vehicular Impact Conditions Associated with Serious Ran-off-Road Crashes,â the Midwest Roadside Safety Facility identified the data needs, developed a data collection plan, conducted a retrospective data collection effort of crashes selected from the National Automotive Sampling System, developed a relational database suitable for future research, and proposed an implementation plan for a long-term data collection effort (The long-term data collection effort is continuing under NCHRP Project 17-43). The data from this study was used in the evaluation of the guardrail runout length calcu- lation procedures and compared to the recommended runout lengths contained in the 2006 AASHTO Roadside Design Guide. The evaluation provides support for reducing the length of guardrail used in advance of roadside obstacles. F O R E W O R D By Charles W. Niessner Staff Officer Transportation Research Board
C O N T E N T S 1 Chapter 1 Introduction 1 1.1 Background 2 1.2 Objective 2 1.3 Scope 3 1.4 Report Organization 4 Chapter 2 Literature Review 4 2.1 In-Depth Crash Data Collection 7 2.2 Impact Conditions of Ran-off-Road Crashes 8 2.3 Data Needs for Study of Ran-off-Road Crashes 9 2.4 Reconstruction of Ran-off-Road Crashes 10 Chapter 3 Study Approach 10 3.1 General 10 3.2 Data Needs 10 3.3 Data Collection Alternatives 13 3.4 Data Collection Protocol 23 3.5 Data from Previous Studies 25 3.6 Relational Database 26 Chapter 4 Results 26 4.1 General 26 4.2 Descriptive Statistics 32 4.3 Departure Conditions 39 4.4 Impact Conditions 48 4.5 Encroachment Length 52 4.6 Significance for Guardrail Runout Length 55 Chapter 5 Long-Term Data Collection Plan 55 5.1 General 56 5.2 Data Collection Alternatives 56 5.3 Proposed Data Collection Plan 58 5.4 Pilot Study 62 5.5 Data Collection ProtocolâContinuous Sampling Subsystem 63 5.6 Data Collection ProtocolâSpecial Studies Subsystem 64 5.7 Summary
65 Chapter 6 Summary of Findings 65 6.1 Study Approach 65 6.2 Findings 65 6.3 Long-Term Data Collection 67 References 69 Appendices Note: Many of the photographs, figures, and tables in this report have been converted from color to grayscale for printing. The electronic version of the report (posted on the web at www.trb.org) retains the color versions.
