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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 766 Recommended Bicycle Lane Widths for Various Roadway Characteristics Darren J. Torbic Karin M. Bauer Chris A. Fees Douglas W. Harwood MRIGlobal Kansas City, MO Ron Van Houten CenteR foR eduCatIon and ReseaRCh In safety Kalamazoo, MI John LaPlante Nathan Roseberry t.y. lIn InteRnatIonal GRoup Chicago, IL Subscriber Categories Pedestrians and Bicyclists ⢠Design ⢠Safety and Human Factors TRANSPORTAT ION RESEARCH BOARD WASHINGTON, D.C. 2014 www.TRB.org 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 766 Project 15-42 ISSN 0077-5614 ISBN 978-0-309-28416-5 Library of Congress Control Number 2014941842 © 2014 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. Cover photograph by Nathan Roseberry, T.Y. Lin International Group.
The National Academy of Sciences is a private, nonprofit, self-perpetuating society of distinguished scholars engaged in scientific and engineering research, dedicated to the furtherance of science and technology and to their use for the general welfare. On the authority of the charter granted to it by the Congress in 1863, the Academy has a mandate that requires it to advise the federal government on scientific and technical matters. Dr. Ralph J. Cicerone is president of the National Academy of Sciences. The National Academy of Engineering was established in 1964, under the charter of the National Academy of Sciences, as a parallel organization of outstanding engineers. It is autonomous in its administration and in the selection of its members, sharing with the National Academy of Sciences the responsibility for advising the federal government. The National Academy of Engineering also sponsors engineering programs aimed at meeting national needs, encourages education and research, and recognizes the superior achievements of engineers. Dr. C. D. Mote, Jr., is president of the National Academy of Engineering. The Institute of Medicine was established in 1970 by the National Academy of Sciences to secure the services of eminent members of appropriate professions in the examination of policy matters pertaining to the health of the public. The Institute acts under the responsibility given to the National Academy of Sciences by its congressional charter to be an adviser to the federal government and, on its own initiative, to identify issues of medical care, research, and education. Dr. Harvey V. Fineberg is president of the Institute of Medicine. The National Research Council was organized by the National Academy of Sciences in 1916 to associate the broad community of science and technology with the Academyâs purposes of furthering knowledge and advising the federal government. Functioning in accordance with general policies determined by the Academy, the Council has become the principal operating agency of both the National Academy of Sciences and the National Academy of Engineering in providing services to the government, the public, and the scientific and engineering communities. The Council is administered jointly by both Academies and the Institute of Medicine. Dr. Ralph J. Cicerone and Dr. C. D. Mote, Jr., are chair and vice chair, respectively, of the National Research Council. The Transportation Research Board is one of six major divisions of the National Research Council. The mission of the Transporta- tion Research Board is to provide leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisciplinary, and multimodal. The Boardâs varied activities 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 individu- als interested in the development of transportation. www.TRB.org www.national-academies.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 reported herein was performed under NCHRP Project 15-42. This report was prepared by Dr. Darren J. Torbic, Ms. Karin M. Bauer, Mr. Chris A. Fees, and Mr. Douglas W. Harwood of MRIGlobal; Dr. Ron Van Houten of Center for Education and Research in Safety (CERS); and Mr. John LaPlante and Mr. Nathan Roseberry of T.Y. Lin International Group. The authors wish to thank the cities of Chicago (IL) and Cambridge (MA) for their assistance in this research. CRP STAFF FOR NCHRP REPORT 766 Christopher W. Jenks, Director, Cooperative Research Programs Christopher Hedges, Manager, National Cooperative Highway Research Program Sheila A. Moore, Program Associate Eileen P. Delaney, Director of Publications Doug English, Editor NCHRP PROJECT 15-42 PANEL Field of DesignâArea of General Design Richard Moeur, Arizona DOT, Phoenix, AZ (Chair) Eric Glick, Nevada DOT, Carson City, NV Steven E. Bowman, Iowa DOT, Ames, IA Denise Chaplick, Michael Baker Corporation, Newark, NJ Dwight L. Kingsbury, Florida DOT (retired), Tallahassee, FL Thobias M. Sando, University of North Florida, Jacksonville, FL Barbara Solberg, Maryland State Highway Administration, Baltimore, MD Larry F. Sutherland, Parsons Brinckerhoff, Columbus, OH Gabriel Rousseau, FHWA Liaison Bernardo Kleiner, TRB Liaison
F O R E W O R D By Christopher J. Hedges Staff Officer Transportation Research Board This report presents recommendations for bicycle lane widths for various roadway and traffic characteristics, including traffic volume, vehicle mix (i.e., percent trucks), lane width and/or total roadway width, and presence/absence of on-street parking. The conclusions are most applicable to urban and suburban roadways with level grade and a posted speed limit of 30 mph and should be used cautiously for the design of roadways with motor vehicle speeds outside of the range of 25 to 35 mph, and in particular for higher-speed roadways. This report will provide valuable guidance for traffic and design engineers in areas where bicycle lanes are being considered and implemented. The 2012 edition of the American Association of State Highway and Transportation Offi- cialsâ Guide for the Development of Bicycle Facilities (AASHTO, 2012), often referred to as the Bike Guide, defines a bicycle lane as âa portion of a roadway that has been designated for preferential or exclusive use by bicyclists by pavement markings and, if used, signs. It is intended for one-way travel, usually in the same direction as the adjacent traffic lane, unless designed as a contra-flow lane.â The AASHTO Bike Guide provides general guidance on appropriate bicycle lane widths. The Bike Guide states that, under most situations, the rec- ommended width for bike lanes is 5 ft, but under several circumstances wider bicycle lane widths may be desirable, and in several cases a 4-ft-wide bike lane can be used. Some transportation agencies use the guidance in the AASHTO Bike Guide to determine appropriate bicycle lane widths, while others have developed their own policies. Whether at the national, state, or local level, the guidelines that have been developed for bicycle lane widths provide only general guidance on how bicycle lane widths should vary based on the conditions of the roadway. Thus, there was a need to conduct scientifically based research to develop more specific guidance on recommended bicycle lane widths for various roadway conditions. Under NCHRP Project 15-42, a research team led by MRIGlobal installed temporary pavement markings at several locations to delineate bicycle lanes of varying widths. The lateral positioning of both bicyclists and motorists was measured and used as surrogates to evaluate the safety effects of the allocation of roadway width between parking lanes, bike lanes, buffered spaces, and motor vehicle travel lanes. The data-collection sites included three midblock locations with on-street parking and two midblock locations where on-street parking was prohibited. The bicycle lane widths evaluated ranged from 3.5 to 6 ft. A supplemental grade study was also performed to evalu- ate lateral movement of bicyclists pedaling on a moderate upgrade. The report presents an analysis of the research and design guidance for bicycle lane widths on existing travel lane widths and parking lane widths. The research is based on a review of literature, the current state of practice, and a series of observational field studies.
C O N T E N T S 1 Summary 4 Section 1 Introduction 4 1.1 Introduction 4 1.2 Research Objective and Scope 4 1.3 Overview of Research Methodology 5 1.4 Outline of Report 6 Section 2 Summary of Literature Review and Design Guidelines 6 2.1 Safety and Design Research Related to Bicycle Lanes and Shared Use Lanes 9 2.2 Domestic and International Guidelines 12 Section 3 Observational Field Studies 12 3.1 Site Selection and Site Characteristics 13 3.2 Study Scenarios 17 3.3 Data Collection Methodology 19 3.4 Data Analysis 49 3.5 Summary of Key Findings 50 Section 4 Supplemental Grade Study 50 4.1 Description of Field Study 50 4.2 Data Analysis 53 4.3 Summary of Key Findings 54 Section 5 Design Guidance 60 Section 6 Conclusions and Future Research 60 6.1 Conclusions 61 6.2 Future Research 63 References
