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Practices in One-Lane Traffic Control on a Two-Lane Rural Highway A Synthesis of Highway Practice Yashar Zeinali Farid David A. Noyce Madhav V. Chitturi Yu Song William F. Bremer Andrea R. Bill Traffic OperaTiOns and safeTy (TOps) LabOraTOry University of WisconsinâMadison Madison, WI 2018 Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration Subscriber Categories Maintenance and Preservation â¢ Operations and Traffic Management â¢ Highways 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 SYNTHESIS 525
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 by going to http://www.national-academies.org and then searching for TRB Printed in the United States of America NCHRP SYNTHESIS 525 Project 20-05, Topic 48-11 ISSN 0547-5570 ISBN 978-0-309-39034-7 Library of Congress Control Number 2018945323 Â© 2018 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. Cover figure: An example of a Red/Yellow automated flagger assistance device. Cover photo credit: Courtesy of Melisa Finley, Texas A&M Transportation Institute NOTICE 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 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. 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 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 identified by chief administrators and other staff of the highway and transportation departments, by committees of AASHTO, and by the Federal Highway Administration. Topics of the highest merit are selected by the AASHTO Special Committee on Research and Innovation (R&I), and each year R&Iâs 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.
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 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.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 CRP STAFF FOR NCHRP SYNTHESIS 525 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Mariela Garcia-Colberg, Senior Program Officer Cheryl Keith, Senior Program Assistant Eileen P. Delaney, Director of Publications Natalie Barnes, Associate Director of Publications Ellen M. Chafee, Senior Editor NCHRP PROJECT 20-05 PANEL Brian A. Blanchard, Florida DOT, Tallahassee, FL (Chair) Stuart D. Anderson, Texas A&M University, College Station, TX Socorro Briseno, California DOT, Sacramento, CA David M. Jared, Georgia DOT, Forest Park, GA Cynthia L. Jones, Ohio DOT, Columbus, OH Malcolm T. Kerley, NXL, Richmond, VA John M. Mason, Jr., Auburn University, Auburn, AL Roger C. Olson, Minnesota DOT, Bloomington, MN (retired) Benjamin T. Orsbon, South Dakota DOT, Pierre, SD Randall R. Park, Utah DOT, Salt Lake City, UT Robert L. Sack, New York State DOT, Albany, NY Francine Shaw Whitson, FHWA, Washington, DC Joyce N. Taylor, Maine DOT, Augusta, ME Jack Jernigan, FHWA Liaison Stephen F. Maher, TRB Liaison TOPIC 48-11 PANEL Mark R. Bortle, Iowa DOT, Ames, IA Benjamin Colucci, University of Puerto RicoâMayaguez, Mayaguez, PR Melisa D. Finley, Texas A&M Transportation Institute (TTI), College Station, TX Justin King, Oregon DOT, Salem, OR Marc A. Mastronardi, Georgia DOT, Atlanta, GA Linda Puffenbarger, Maryland State Highway Administration, LaVale, MD Ed Yarbrough, California DOT, Yuba City, CA Martha C. Kapitanov, FHWA Liaison Katherine A. Petros, FHWA Liaison James W. Bryant, Jr., TRB Liaison
FOREWORD Highway administrators, engineers, and researchers often face problems for which information already exists, either in documented form or as undocumented experience and practice. This infor- mation may be fragmented, scattered, and unevaluated. As a consequence, full knowledge of what has been learned about a problem may not be brought to bear on its solution. Costly research findings may go unused, valuable experience may be overlooked, and due consideration may not be given to recommended practices for solving or alleviating the problem. There is information on nearly every subject of concern to highway administrators and engineers. Much of it derives from research or from the work of practitioners faced with problems in their day- to-day work. To provide a systematic means for assembling and evalu ating such useful information and to make it available to the entire highway community, the American Association of State High- way and Transportation Officialsâthrough the mechanism of the National Cooperative Highway Research Programâauthorized the Transportation Research Board to undertake a continuing study. This study, NCHRP Project 20-05, âSynthesis of Information Related to Highway Problems,â searches out and synthesizes useful knowledge from all available sources and prepares concise, documented reports on specific topics. Reports from this endeavor constitute an NCHRP report series, Synthesis of Highway Practice. This synthesis series reports on current knowledge and practice, in a compact format, without the detailed directions usually found in handbooks or design manuals. Each report in the series provides a compendium of the best knowledge available on those measures found to be the most successful in resolving specific problems. PREFACE By Mariela Garcia-Colberg Staff Officer Transportation Research Board Temporary traffic control, also known as maintenance of traffic, is critical to minimizing conges- tion and maintaining mobility during planned and unplanned activities as well as providing a safe work zone for both road users and workers. This synthesis identifies innovative practices and devices for establishing one-lane traffic control on rural two-lane highways. A literature review and detailed survey responses from 45 (of 50) departments of transportation (90% response rate) are presented. Innovative examples of one-lane two-way traffic control opera- tions at roundabouts and applications of temporary portable rumble strips and driveway assistance devices are also discussed in this synthesis, providing additional insights on the state of the practice. The information presented in this synthesis will be extremely useful to state agencies as they review their current practices regarding one-lane traffic control on two-way rural highways and assess what changes to their current procedures they can implement. This synthesis was prepared by David A. Noyce and his team from the University of Wisconsinâ Madison. The members of the topic panel are acknowledged on the preceding page. This synthesis is an immediately useful document that records the practices that were acceptable within the limita- tions of the knowledge available at the time of its preparation. As progress in research and practice continues, new knowledge will be added to that now at hand.
1 Summary 5 Chapter 1 Introduction 5 Objectives 6 Scope 6 Definition 6 Study Methodology 7 Synthesis Organization 8 Chapter 2 Literature Review 8 TTC Zone 8 Types of 1L2W Operations 23 Traffic Analysis 24 Treatments for Side Roads and Driveways 25 Equipment to Augment Manual Flagging 26 Flagger Apparel 27 Night Flagging 31 Enhanced/Electronic Advance Signing 32 End-of-Queue Warning 33 Evaluation of Different Methods 34 Proper Method Selection 35 Summary 36 Chapter 3 Survey Questionnaire and Interview Summary: An Overview of the Current State of Practice 37 Traffic Analysis 41 Design Thresholds 43 Methods 74 Side Road and Driveway Treatment 78 End-of-Queue Management 78 Mandatory Use of PCMSs 78 Project Coordination 79 Special Roadway Geometrics 82 Speed Control Methods 82 ITSs 82 Summary 84 Chapter 4 Case Examples 84 Roundabouts 84 TPRSs 93 DADs 99 Summary C O N T E N T S
101 Chapter 5 Conclusions and Future Research 101 Conclusions 103 Future Research 104 Appendix A Traffic Analysis For 1L2W Operations 115 Appendix B Survey Questionnaire 128 Appendix C Survey Results on Affecting Factors 136 Appendix D Survey Respondents 138 References 142 Acronyms, Abbreviations, and Initialisms 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.trb.org) retains the color versions.