Motorcycle Crashes into Traffic Barriers: Factors Related to Serious and Fatal Injuries (2022)

Below is the uncorrected machine-read text of this chapter, intended to provide our own search engines and external engines with highly rich, chapter-representative searchable text of each book. Because it is UNCORRECTED material, please consider the following text as a useful but insufficient proxy for the authoritative book pages.

2022 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 1005 Motorcycle Crashes into Trafc Barriers FACTORS RELATED TO SERIOUS AND FATAL INJURIES Hampton C. Gabler Allison Daniello Whitney Tatem Ada Tsoi Virginia Polytechnic Institute and State University Blacksburg, VA Douglas J. Gabauer Bucknell University Lewisburg, PA Joel Stitzel Joel Sink Ryan Barnard Wake Forest University Winston-Salem, NC Subscriber Categories Operations and Trafc Management • Safety and Human Factors Research sponsored by the American Association of State Highway and Transportation Ofcials in cooperation with the Federal Highway Administration

NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state departments of transportation (DOTs) administrators and engineers. Often, highway problems are of local or regional interest and can best be studied by state DOTs individually or in cooperation with their state universities and others. However, the accelerating growth of highway transporta- tion results in increasingly complex problems of wide interest to high- way 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 techniques—the 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 (FHWA), United States Department of Transportation, under Agree- ment No. 693JJ31950003. 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 TRB’s 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; TRB’s relationship to the National Academies is an insurance of objectivity; and TRB maintains a full-time staff of special- ists in highway 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 iden- tified by chief administrators and other staff of the highway and transportation departments, by committees of AASHTO, and by the FHWA. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&I’s recommendations are proposed to the AASHTO Board of Direc- tors and the National 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 National Academies 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 https://www.mytrb.org/MyTRB/Store/default.aspx Printed in the United States of America NCHRP RESEARCH REPORT 1005 Project 22-26 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-68743-0 Library of Congress Control Number 2022946391 © 2022 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trade- marks of the 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, APTA, FAA, FHWA, FTA, GHSA, or NHTSA 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; the FHWA; or the program sponsors. The Transportation Research Board does not develop, issue, or publish standards or specifi- cations. The Transportation Research Board manages applied research projects which pro- vide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications. 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 manufacturers’ names or logos appear herein solely because they are considered essential to the object of the report.

e 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. e 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. John L. Anderson is president. e 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. e 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. e National 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.nationalacademies.org. e Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. e mission of the Transportation Research Board is to provide leadership in transportation improvements and innovation through trusted, timely, impartial, and evidence-based information exchange, research, and advice regarding all modes of transportation. e Board’s varied activities annually engage about 8,000 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. e 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 team wishes to acknowledge the late Charles Niessner, the initial NCHRP Project 22-26 program officer and friend, for his guidance in the initial phase of this project. We gratefully acknowledge Katie Kennedy and Bill Martin, Wake Forest University Medical Center, for developing the Patient Enroll- ment Sheet, the Eye Witness Statement Sheet, and the Motorcyclist/Eyewitness Interview Datasheet. This project would not have been possible without the assistance of Virginia Polytechnic Institute and State University graduate students Ada Tsoi, Whitney Tatem, and Jackey Chen, who organized many of the case reviews for the in-depth crash investigations. We also want to thank David Mersfelder and Martin Hageman, principal engineers in the Harley- Davidson Product Integrity department, for their assistance in performing an independent case review of two of our in-depth crash investigation cases. Special thanks to Professors Richard McGinnis and Cara Wang of Bucknell for their expert insights during the initial phase of this project. Our thanks to the University of Maryland School of Medicine and Dr. Pat Dischinger for their contribution of the MD-CODES data and for their expertise and the use of this unique dataset. We gratefully acknowledge the FHWA and University of North Carolina Highway Safety Research Center for providing the HSIS data used in this study. CRP STAFF FOR NCHRP RESEARCH REPORT 1005 Christopher J. Hedges, Director, Cooperative Research Programs Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program Sid Mohan, Associate Program Manager, Implementation and Technology Transfer, National Cooperative Highway Research Program David M. Jared, Senior Program Officer Clara Schmetter, Senior Program Assistant Natalie Barnes, Director of Publications Heather DiAngelis, Associate Director of Publications Margaret B. Hagood, Senior Editor NCHRP PROJECT 22-26 PANEL Field of Design—Area of Vehicle Barrier Systems David A. Noyce, University of Wisconsin, Madison, Madison, WI (Chair) Mark L. Brown, North Carolina State Highway Patrol, Raleigh, NC David Anson Chesson, Burlington, WA Bernie Clocksin, South Dakota Department of Transportation (retired), Pierre, SD Don Jay Gripne, DJG NW INC, Olympia, WA David James Lindeman, Winnemucca, NV Chris Poole, Iowa Department of Transportation, Ames, IA Richard B. Albin, FHWA Liaison Bernardo B. Kleiner, TRB Liaison

NCHRP Research Report 1005 provides support for implementation of motorcyclist pro- tection systems (MPS) in the United States. MPS are traffic barriers specifically designed to mitigate the consequences of a motorcycle-barrier impacts and typically fall into two categories: (1) devices that reduce the severity of impacts with barrier posts through post redesign or shielding, and (2) devices that prevent impact with barrier posts by the addition of a lower rail element or redesign of the rail element. While MPS are used internationally, only a small number of MPS pilot installations are currently present in the United States. The findings of this report confirm an elevated injury risk for motorcyclists in collisions with traffic barriers and support implementation of MPS via the following: (a) development of a motorcycle-barrier crash test that considers rider orientation and injury; (b) conducting a motorcycle-barrier test with roadside hardware; (c) evaluating MPS using four-wheeled vehicles; (d) evaluating the performance of existing MPS pilot installations; and (e) devel- oping methods to determine where to locate MPS. Guidelines on how to reduce the risk of injury for motorcyclists in collisions with traffic barriers do not currently exist. MASH crash test procedures, which have been successful in ensuring safer barrier designs for cars and light trucks, do not prescribe a crash test proce- dure for motorcycles. Most research on MPS or motorcycle-barrier crash testing has been conducted outside the United States, and little has been published in recent years on the characteristics of motorcycle-barrier crashes in the United States or on potential solutions. Under NCHRP Project 22-26, “Factors Related to Serious Injury and Fatal Motorcycle Crashes with Traffic Barriers,” Virginia Tech was asked to identify factors that contribute to serious and fatal injury in motorcycle-barrier collisions. A focus was on guardrail, con- crete, and cable barrier collisions, and factors that influence injury. Data analyzed included national and state crash data, state crash data matched with hospital records or roadway data, and 22 in-depth motorcycle-barrier crashes collected during the project. The available data was used to investigate national motorcycle fatality risk by object struck, injury risk by barrier type, rider post-impact trajectory, associated roadway characteristics, specific injuries sustained, and injury mechanisms. The findings confirm an elevated injury risk for motorcyclists in collisions with traffic barriers and support implementation of MPS in the United States. The conduct of research report is provided in NCHRP Research Report 1005 and the report appendices in NCHRP Web-only Document 327: Serious and Fatal Motorcycle Crashes into Traffic Barriers: Injury Information. These materials are available on the National Academies Press website (www.nap.edu) and can be found by searching for NCHRP Research Report 1005: Motorcycle Crashes into Traffic Barriers: Factors Related to Serious and Fatal Injuries. F O R E W O R D By David M. Jared Staff Officer Transportation Research Board

1 Summary 8 Chapter 1 Introduction 8 1.1 Consideration of Barrier Types 10 1.2 Research Problem Statement 11 1.3 Objectives and Scope 12 Chapter 2 Research Approach 12 2.1 Synthesis of Current U.S. and International Literature 12 2.2 Analysis of National and State Crash Databases 13 2.3 In-Depth Investigations of Motorcycle-Barrier Crashes 16 2.4 Injury Scoring 17 2.5 Description of Anticipated Results 18 Chapter 3 Synthesis of Current U.S. and International Literature on Serious Injury and Fatal Motorcycle Crashes into Traffic Barriers 18 3.1 Approach 18 3.2 Motorcycle-Barrier Crash Characteristics 29 3.3 Motorcycle-Barrier Injury Mechanisms 33 3.4 Motorcycle-Barrier Crash Testing 37 3.5 Potential Motorcycle-Barrier Crash Countermeasures 40 3.6 Pilot Tests of MPS in the United States 40 3.7 Data Collection Methodology 42 3.8 Conclusions 44 3.9 Gaps and Research Needs 45 Chapter 4 Characteristics of Fatal Motorcycle-to-Guardrail Crashes 45 4.1 Introduction 45 4.2 Objective 45 4.3 Methods 46 4.4 Results 55 4.5 Conclusions 56 Chapter 5 Fatality Risk in Motorcycle Collisions with Roadside Objects in the United States 56 5.1 Introduction 56 5.2 Objective 57 5.3 Methods 58 5.4 Results 61 5.5 Discussion 61 5.6 Conclusions C O N T E N T S

62 Chapter 6 Relationship Between Barrier Type and Injury Severity 62 6.1 Introduction 62 6.2 Objective 62 6.3 Methods 64 6.4 Results 70 6.5 Discussion 71 6.6 Conclusions 72 Chapter 7 Relationship Between Rider Trajectory and Injury Outcome in Motorcycle-to-Barrier Crashes 72 7.1 Introduction 72 7.2 Objective 72 7.3 Methods 75 7.4 Results 79 7.5 Discussion 80 7.6 Conclusions 81 Chapter 8 Characteristics of Injuries in Motorcycle-to-Barrier Collisions in Maryland 81 8.1 Introduction 81 8.2 Objective 81 8.3 Methods 82 8.4 Results 89 8.5 Limitations 89 8.6 Conclusions 91 Chapter 9 Roadway Characteristics Associated with Motorcycle Crashes into Longitudinal Barriers and the Influence on Rider Injury 91 9.1 Introduction 91 9.2 Objective 92 9.3 Background and Previous Research 94 9.4 Methodology 97 9.5 Results 102 9.6 Discussion 103 9.7 Conclusions 104 Chapter 10 In-Depth Investigation of Injury Mechanisms in Motorcycle-to-Barrier Crashes 104 10.1 Objective 104 10.2 Methods 108 10.3 Results 112 10.4 Discussion 114 10.5 Limitations 115 Chapter 11 Conclusions 115 11.1 Research Findings 121 11.2 Recommendations 123 References Note: Photographs, figures, and tables in this report may have been converted from color to grayscale for printing. The electronic version of the report (posted on the web at www.nap.edu) retains the color versions.