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Utility Pole Safety and Hazard Evaluation Approaches A Synthesis of Highway Practice Charles Zegeer Chapel Hill, NC Paul Scott Dumfries, VA Don L. Ivey Bryan, TX Kevin Zegeer Chapel Hill, NC 2020 Research sponsored by the American Association of State Highway and Transportation Officials in cooperation with the Federal Highway Administration Subscriber Categories Design â¢ Highways â¢ Safety and Human Factors 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 557
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 https://www.nationalacademies.org and then searching for TRB Printed in the United States of America NCHRP SYNTHESIS 557 Project 20-05, Topic 50-04 ISSN 0547-5570 ISBN 978-0-309-48174-8 Library of Congress Control Number 2020941416 Â© 2020 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, FTA, GHSA, NHTSA, 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. 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; the FHWA; 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, 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 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 (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 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 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&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. John L. Anderson 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.nationalacademies.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 provide leadership in transportation improvements and innovation through trusted, timely, impartial, and evidence-based information exchange, research, and advice regarding all modes of transportation. The Boardâs 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. 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 557 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Tanya M. Zwahlen, Senior Program Officer Deborah Irvin, Program Coordinator Eileen P. Delaney, Director of Publications Natalie Barnes, Associate Director of Publications NCHRP PROJECT 20-05 PANEL Joyce N. Taylor, Maine Department of Transportation, Augusta, ME (Chair) Socorro âCocoâ A. Briseno, Sacramento, CA Anita K. Bush, Nevada Department of Transportation, Carson City, NV Joseph D. Crabtree, Kentucky Transportation Center, Lexington, KY Mostafa Jamshidi, Nebraska Department of Transportation, Lincoln, NE Cynthia L. Jones, Ohio Department of Transportation, Columbus, OH Jessie X. Jones, Arkansas Department of Transportation, Little Rock, AR Brenda Moore, North Carolina Department of Transportation, Raleigh, NC Ben T. Orsbon, South Dakota Department of Transportation, Pierre, SD Randall R. Park, Avenue Consultants, Taylorsville, UT Brian Worrel, Iowa Department of Transportation, Ames, IA Jack D. Jernigan, FHWA Liaison Jim T. McDonnell, AASHTO Liaison Stephen F. Maher, TRB Liaison TOPIC 50-04 PANEL Patrick Allen, Georgia Department of Transportation, Atlanta, GA Pamela R. Blazo, Michigan Department of Transportation, Lansing, MI Christine E. Carrigan, Road Safe LLC, Canton, ME Eric C. Cimo, Delaware Department of Transportation, Dover, DE H. David Cordova, California Department of Transportation (CALTRANS), Sacramento, CA Dhafer Marzougui, George Mason University, Fairfax, VA Ahmer Nizam, Washington State Department of Transportation, Olympia, WA Menna Yassin, FHWA Liaison Nelson H. Gibson, TRB Liaison AUTHOR ACKNOWLEDGMENTS The authors appreciate the time and input from the project panel, the STA representatives, and the utility owners. We also wish to thank Chris Gomola, the librarian at the UNC Highway Safety Research Center, for her help in finding available publications; Tanya Zwahlen, the project manager; and Sallie Chafer, the report editor. Their assistance was essential in the writing of this synthesis.
ABOUT THE NCHRP SYNTHESIS PROGRAM 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. FOREWORD By Tanya M. Zwahlen Staff Officer Transportation Research Board The objective of this NCHRP Synthesis 557 is to summarize the strategies, policies, and tech- nologies that state transportation agencies (STAs) and utility companies use to address potential utility pole hazards. The report documents how STAs and utility companies identify, evaluate, and successfully address these concerns. The state of practices was examined through a review of literature, an online survey of state transportation agencies, and interviews with state transportation agencies, which led to the creation of case examples highlighting successful strategies, policies, and technologies that address potential utility pole hazards. Charlie Zegeer collected and synthesized the information and wrote the report. 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 limitations of the knowledge available at the time of its preparation.
1 Summary 9 Chapter 1 Introduction 9 The Utility Pole Problem 12 Report Objective 12 Agency Surveys 12 Literature Review 14 Chapter 2 Historical Perspective 14 Statement of the Problem 14 AASHTO Design Guidelines 16 Challenge of Utility Pole Crashes 18 Chapter 3 Summary of STA Survey Responses 18 Utility Pole-Placement Guidelines 19 Exceptions to Placement Guidelines 19 Utility Pole Crashes 20 High-Crash Location Tracking 22 Identifying High-Risk Poles 22 STA Countermeasures in Use 24 Funding 24 Local and Utility Owner Policies 25 Chapter 4 Factors Associated with Utility Pole Crashes 25 Factors Related to Crash Frequency 26 Factors Related to Pole Crash Severity 26 Safety Appurtenances 27 Research on Utility Pole Crash Prediction 34 Chapter 5 Identification of Utility Poles in High-Risk Locations 38 Chapter 6 Countermeasure Cost-Effectiveness 39 Place Utility Lines Underground and Remove Utility Poles 39 Relocate Utility Poles Further from the Roadway 39 Reduce Pole Density 40 Combine Reducing Pole Density and Relocating Poles Further from the Road 40 Convert to Steel-Reinforced Safety (Breakaway) Poles 41 Assess Countermeasure Cost-Effectiveness 41 Select Cost-Effective Countermeasures 45 Chapter 7 Current Countermeasure Practices 45 Studies of Individual Treatments, Past and Present 53 Full Range of Possible Solutions and Countermeasures C O N T E N T S
54 Chapter 8 Safety Devices 55 Crash Cushions 55 Composite Utility Poles 56 Steel-Reinforced Safety Poles 58 Low-Profile Barrier 58 Guardrails and Various Terminals 58 Breakaway Guy Wires 59 Delineation 60 Buried Duct Network of Cables 61 Chapter 9 STA Case Examples 62 Washington State DOT 63 Georgia DOT 64 New Jersey DOT 65 North Carolina DOT 65 Anonymous DOT 66 Other Case Examples 68 Chapter 10 Utility Owner Case Examples 68 Utility Owner Case Example 1 68 Utility Owner Case Example 2 69 Utility Owner Case Example 3 69 Utility Owner Case Example 4 70 Chapter 11 Conclusions 70 Study Purpose 70 Results of the STA Survey 70 Utility Placement Guidelines 71 Exceptions to Pole-Placement Guidelines 71 Utility Pole Crashes 72 Tracking High-Risk Poles 72 Identifying High-Risk Poles 72 Countermeasures in Use 72 Funding 73 Local and Utility Owner Policies 73 Factors Related to Utility Pole Crashes 73 Utility Poles at High-Risk Locations 73 Cost-Effectiveness Treatments 74 STA and UO Utility Pole Treatment Options 75 Example of a Logical Approach to a Utility Pole Safety Program 75 Examples of Utility Pole Safety Initiatives 75 Implications of Synthesis 77 Current Gaps in Knowledge 77 Future Research Areas 79 References and Bibliography 82 Glossary 85 Abbreviations
A-1 Appendix A State DOT Utility-Related Websites, 2019 B-1 Appendix B Summary of Survey Results C-1 Appendix C Countermeasure Cost-Effectiveness Summary D-1 Appendix D FHWA Program Guide: Utility Relocation and Accommodation on Federal-Aid Highway Projects E-1 Appendix E Utility Pole and Tree Safety Case Studies F-1 Appendix F Example of Recommended Crash Reduction Program and Roadside Safety Treatments G-1 Appendix G Examples of STA Guidelines with Safety Implications 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.