Guidance for the Design and Application of Shoulder and Centerline Rumble Strips (2009)

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.

TRANSPORTAT ION RESEARCH BOARD WASHINGTON, D.C. 2009 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 641 Subject Areas Safety and Human Performance Guidance for the Design and Application of Shoulder and Centerline Rumble Strips D. J. Torbic J. M. Hutton C. D. Bokenkroger K. M. Bauer D. W. Harwood D. K. Gilmore J. M. Dunn J. J. Ronchetto MIDWEST RESEARCH INSTITUTE Kansas City, MO E. T. Donnell H. J. Sommer III P. Garvey PENNSYLVANIA TRANSPORTATION INSTITUTE PENNSYLVANIA STATE UNIVERSITY University Park, PA B. Persaud C. Lyon Toronto, Canada 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 Board’s 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 641 Project 17-32 ISSN 0077-5614 ISBN 978-0-309-11799-9 Library of Congress Control Number 2009935878 © 2009 Transportation Research Board COPYRIGHT PERMISSION 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. Such approval reflects the Governing Board’s judgment that the program concerned is of national importance and appropriate with respect to both the purposes and resources of the National Research Council. The members of the technical committee selected to monitor this project and to review this report were chosen for recognized scholarly competence and with due consideration for the balance of disciplines appropriate to the project. The opinions and conclusions expressed or implied are those of the research agency that performed the research, and, while they have been accepted as appropriate by the technical committee, they are not necessarily those of the Transportation Research Board, the National Research Council, the American Association of State Highway and Transportation Officials, or the Federal Highway Administration, U.S. Department of Transportation. Each report is reviewed and accepted for publication by the technical committee according to procedures established and monitored by the Transportation Research Board Executive Committee and the Governing Board of the National Research Council. The Transportation Research Board of the National Academies, the National Research Council, the Federal Highway Administration, the American Association of State Highway and Transportation Officials, and the individual states participating in the National Cooperative Highway Research Program do not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered essential to the object of this report.

CRP STAFF FOR NCHRP REPORT 641 Christopher W. Jenks, Director, Cooperative Research Programs Crawford F. Jencks, Deputy Director, Cooperative Research Programs Charles W. Niessner, Senior Program Officer Eileen P. Delaney, Director of Publications NCHRP PROJECT 17-32 PANEL Field of Traffic—Area of Safety Benjamin H. Cottrell, Jr., Virginia DOT (Chair) David Bachman, Pennsylvania DOT Mark O. Christensen, Horrocks Engineers, Pleasant Grove, UT Troy A. Jerman, Iowa DOT Frank C. Julian, Jr., FHWA Ali Kamyab, Sacramento, CA Wayne Kinder, Carson City, NV Erika B. Lindenberg, Connecticut DOT Susan G. Miller, Freeborn County, MN David K. Olson, Washington State DOT Gerald E. Willhelm, H.W. Lochner, Inc., Bellevue, WA Roya Amjadi, FHWA Liaison Richard Pain, TRB Liaison AUTHOR ACKNOWLEDGMENTS The report was prepared by Dr. Darren J. Torbic, Ms. Jessica M. Hutton, Ms. Courtney D. Bokenkroger, Ms. Karin M. Bauer, Mr. Douglas W. Harwood, Mr. David K. Gilmore, Ms. Joanna M. Dunn, and Mr. John J. Ronchetto of Midwest Research Institute (MRI); Dr. Eric T. Donnell, Dr. Henry J. Sommer III, and Mr. Philip Garvey of the Pennsylvania Transportation Institute (PTI) at the Pennsyl- vania State University; and consultants Dr. Bhagwant Persaud and Mr. Craig Lyon. The authors wish to thank the state departments of transportation of Minnesota, Missouri, Pennsylvania, and Washington for their assistance in the safety evaluations. Finally, the authors acknowledge Dr. Bohdan Kulakowski, a member of the research team who passed away during the course of this research. His wisdom and friend- ship will be greatly missed. 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 provides guidance for the design and application of shoulder and centerline rumble strips as an effective crash reduction measure, while minimizing adverse effects for motorcyclists, bicyclists, and nearby residents. Using the results of previous studies and the research conducted under this project, safety effectiveness estimates were developed for shoulder rumble strips on rural freeways and rural two-lane roads and for centerline rum- ble strips on rural and urban two-lane roads. The report will be of particular interest to safety practitioners with responsibility for roadway design. Shoulder rumble strips have demonstrated effectiveness in reducing lane-departure crashes on rural freeways. Because they have proven to be cost-effective countermeasures, state departments of transportation and local agencies want to expand the use of rumble strips along the shoulders of divided and undivided highways and along the centerline of undivided highways including two-lane roadways. However, installing rumble strips to reduce run-off-the-road or centerline crossover crashes, with no consideration of impacts to other users, may lead to unintended outcomes. Some of the unresolved issues with installing either shoulder or centerline rumble strips include: • Minimum dimensions of the rumble strips necessary for effective vehicular warning with least potential for adverse effects; • Optimal placement, including minimum criteria for lane and shoulder widths; • Optimal longitudinal gaps in rumble strips to provide accessibility for bicyclists while maintaining the effectiveness in reducing lane departures; • Effectiveness and alternative designs for various speeds; • Physical design of rumble strips with respect to “rideability” for motorcyclists and bicy- clists; and • Noise produced by rumble strips on adjacent residents. The shoulders of the highway system are a diverse environment, with usage by bicyclists, pedestrians, mail carriers, school buses, and farm vehicles. There is great variability in shoul- der widths, materials, and pavement depths, making uniform application difficult. The optimal placement of the rumble strips in relation to the edgeline is also in question. Fur- ther, shoulders are used for lane shifts during construction and maintenance operations, requiring vehicles to drive over the rumble strips which may result in driver discomfort and potential operational problems. F O R E W O R D By Charles W. Niessner Staff Officer Transportation Research Board

Although information is limited, there is evidence that centerline rumble strips are an effective countermeasure for reducing centerline crossover collisions. However, centerline rumble strips raise concerns regarding pavement durability at centerline joints, their use in passing zones, and their impact on motorcyclists. Under NCHRP Project 17-32, “Guidance for the Design and Application of Shoulder and Centerline Rumble Strips,” the research team led by Midwest Research Institute (MRI) investigated the (a) safety effectiveness of shoulder rumble strips on different types of roads, (b) optimal placement of shoulder rumble strips with respect to the edgeline, (c) optimal dimensions of shoulder rumble strips necessary for effective vehicular warning with least potential adverse effects, and (d) minimum level of stimuli necessary to alert a drowsy or inattentive driver. MRI also investigated the safety effectiveness of centerline rumble strips on different types of roads, for varying roadway geometry, and in combination with shoul- der rumble strips. The report includes estimates of the safety effectiveness of shoulder and centerline rum- ble strips, recommends the placement of shoulder rumble strips with respect to the edge- line, recommends sound level differences in the passenger compartment to alert drivers, and provides equations for determining rumble strip dimensions for a range of operating conditions.

C O N T E N T S 1 Summary 5 Section 1 Introduction 5 Background 5 Research Objective and Scope 6 Organization of This Report 7 Section 2 Magnitude and Nature of Highway Safety Concerns Related to Shoulder and Centerline Rumble Strips 7 SVROR Crashes 9 Head-On Crashes 10 Drowsy and Fatigued Driving 11 Crashes and Heavy Vehicles 12 Summary 13 Section 3 Purpose, Types, and Dimensions of Rumble Strips 13 Purpose of Rumble Strips 13 Types of Rumble Strips 14 Dimensions of Rumble Strips 16 Section 4 Review of Completed Shoulder and Centerline Rumble Strip Research 16 Safety Impacts of Shoulder Rumble Strips 16 Safety Impacts of Centerline Rumble Strips 18 Operational Impacts of Centerline Rumble Strips 19 Vehicle Dynamics Related to Vibration and Noise Stimuli 19 Effects of Rumble Strips on Specific Types of Highway Users 20 Pavement Performance Issues 21 Other Potential Concerns 23 Section 5 Existing Rumble Strip Practices and Policies 23 Typical Shoulder and Centerline Rumble Strip Practices in North America 32 Summary of Survey Responses 38 Summary of Key Findings From Existing Rumble Strip Practices and Policies 42 Section 6 Safety Effectiveness of Shoulder Rumble Strips 43 Scope of Safety Evaluation 43 Site Selection 47 Videolog Data Collection 50 Database Development 51 Descriptive Statistics 58 Analysis Approach

66 Analysis Results 91 Summary of Key Findings 92 Section 7 Safety Effectiveness of Centerline Rumble Strips 93 Scope of Safety Evaluation 93 Site Selection 95 Videolog Data Collection 96 Database Development 97 Descriptive Statistics 102 Analysis Approach 106 Analysis Results 113 Summary of Key Findings 114 Section 8 Stimuli Levels for Effective Rumble Strips 115 Overview 115 Psychophysics 116 FMCSA, FHWA, and NSF Interviews 116 Field Data 118 Summary of Key Findings 119 Section 9 Optimum Dimensions for Rumble Strips 120 Data Acquisition Methodology 120 Field Data Collection 124 Analysis Approach 124 Analysis Results 129 Application of the Noise Models 134 Summary of Key Findings 135 Section 10 Rumble Strip Application and Design Criteria 135 Implications on Shoulder Rumble Strip Policies 140 Implications on Centerline Rumble Strip Policies 143 Section 11 Conclusions and Recommendations for Future Research 143 Conclusions 144 Recommendations for Future Research 147 Section 12 References 151 Acronyms 152 Appendix A Detailed Literature Review 152 Appendix B Survey Questionnaire 152 Appendix C Detailed Summary of Survey Results 153 Appendix D Roadside Hazard Rating Category Descriptions 158 Appendix E SPF Results for TOT, FI, SVROR, and SVROR FI Crashes on Selected Roadways Without Shoulder Rumble Strips 161 Appendix F GLM Analysis Results for Safety Effectiveness of Shoulder Rumble Strips

166 Appendix G GLM Analysis Results for Effect of Shoulder Rumble Strip Offset and Recovery Area on Safety 170 Appendix H SPF Results for TOT, FI, and SSOD Crashes on Selected Roadways Without Centerline Rumble Strips