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2021 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 876 Guidelines for Integrating Safety and Cost-Effectiveness into Resurfacing, Restoration, and Rehabilitation (3R) Projects Douglas W. Harwood Daniel J. Cook MRIGlobal Kansas City, MO Richard C. Coakley CH2M Hill Milwaukee, Wisconsin Chad Polk CH2M Hill Tampa, Florida Subscriber Categories Design 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, 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. 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 876 Project 15-50 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-67405-8 Library of Congress Control Number 2021939571 © 2021 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 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; 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 or logos appear herein solely because they are considered essential to the object of the report.
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 RESEARCH REPORT 876 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs B. Ray Derr, Senior Program Officer Anthony P. Avery, Senior Program Assistant Eileen P. Delaney, Publications Senior Advisor Natalie Barnes, Director of Publications Janet M. McNaughton, Senior Editor NCHRP PROJECT 15-50 PANEL Field of DesignâArea of General Design Priscilla A. Tobias, Arora and Associates, P.C., Springfield, IL (Chair) Jonathan Marburger, JEO Consulting Group, Lawrence, KS Simone Ardoin, Louisiana DOTD, Baton Rouge, LA Moreshwar Kulkarni, Maryland Department of Transportation, Baltimore, MD John Mason, Pennsylvania State University, Harrisburg, PA Aurora Meza, VRX, Inc., Austin, TX Larry F. Sutherland, Parsons Brinckerhoff, Columbus, OH Dale Widner, California DOT, Redding, CA Jeffrey B. Shaw, FHWA Liaison James W. Bryant, Jr., TRB Liaison AUTHOR ACKNOWLEDGMENTS Richard Coakley and Chad Polk are currently with Jacobs in Atlanta, Georgia, and Tampa, Florida, respectively. Jacobs acquired CH2M Hill in December 2017.
NCHRP Research Report 876 presents a rational approach for estimating the cost- effectiveness of including safety and operational improvements in a resurfacing, restora- tion, or rehabilitation (3R) project. The approach uses the performance of the existing road in estimating the benefits and cost-effectiveness of proposed design improvements. These guidelines are intended to replace TRB Special Report 214: Designing Safer Roads: Practices for Resurfacing, Restoration, and Rehabilitation. The guidelines are accompanied by two spreadsheet tools, one for analyzing a single design alternative and one for comparing several alternatives or combinations of alternatives. Prior to 1976, federal highway funds could only be used for the construction of new highways or the reconstruction of existing highways. The Federal-Aid Highway Act of 1976 allowed the use of federal aid for resurfacing, restoration, and rehabilitation (3R) projects on federal-aid highways. However, in 1976 there were no standards for 3R improvements. Transportation agencies relied on standards for new or reconstructed roadways in AASHTOâs A Policy on Geometric Design of Highways and Streets (the âGreen Bookâ), and, where the proposed geometric elements did not meet the AASHTO guidelines on a 3R project, design exceptions or exemptions had to be sought. In response to a provision in the Surface Transportation Assistance Act of 1982, the Secretary of Transportation requested the National Academy of Sciences (now the National Academies of Sciences, Engineering, and Medicine) to study the cost-effectiveness of geometric design standards and recom- mend minimum standards for 3R projects on existing federal-aid highways, except free- ways. The purpose of 3R standards was twofold: (1) to identify minimum standards for selective geometric elements for which 3R funding could be used to maintain existing highways in an effort to extend their service life and (2) to provide transportation agencies with the ability to make cost-effective improvements to existing highways for selective geometric elements to enhance safety and reduce crashes. The result of this study was Special Report 214: Designing Safer Roads: Practices for Resurfacing, Restoration, and Reha- bilitation, published in 1987. Since 1987, values for many of the design elements within the AASHTO Green Book have been revised, including FHWAâs designated 13 controlling criteria, and the cost of construction has changed. Incremental geometric design improvements in 3R projects can be cost-effective and have significant payoffs in safety and operational benefits. Further- more, with the publication of the AASHTO Highway Safety Manual and other recent publications, additional knowledge is available regarding the relationship of geometric elements to the frequency and severity of crashes. F O R E W O R D By B. Ray Derr Staff Officer Transportation Research Board
In NCHRP Project 15-50, MRIGlobal reviewed the literature and state of the practice for designing 3R projects. It also reviewed the latest research on the safety impacts of design improvements and developed cost-benefit analysis equations for the most common design improvements applied to 3R projects. This effort was supported by the development of spreadsheet tools for evaluating alternative designs. Both spreadsheet tools can be down- loaded from the TRB website (trb.org) by searching for âNCHRP Research Report 876â. The final research results reflect the experience of six state departments of transportation in applying the draft design guidelines and supporting materials. This occurred under NCHRP Project 15-50(01), âImplementation Assessment of 3R Design Guidelines.â
1 Summary 5 Chapter 1 Introduction 5 1.1 Purpose of Guidelines 5 1.2 Scope of Guidelines 6 1.3 History of Guidelines 7 1.4 Organization of Report 8 Chapter 2 What Are 3R Projects? 8 2.1 New Construction Versus Reconstruction Versus 3R Projects 9 2.2 Objectives of 3R Projects 9 2.3 Typical Improvements Made in 3R Projects in Addition to Resurfacing 11 Chapter 3 Process for 3R Project Development 11 3.1 How Does the Design Process for 3R Projects Differ from That for New Construction and Reconstruction Projects? 13 3.2 How Should Candidate 3R Projects Be Identified? 14 3.3 Assessment of Needs for Improvements in Addition to Resurfacing 19 Chapter 4 Managing a 3R Program to Reduce Crash Frequency and Severity 19 4.1 Role of 3R Projects in Overall Safety Management Programs of Highway Agencies 20 4.2 Quantifying the Crash Reduction Effectiveness of 3R Improvements: Crash Modification Factors 23 4.3 Crash Modification Factors for Specific Types of 3R Improvements 42 4.4 Investing Available 3R Funds for Maximum Reduction of Crash Frequency and Severity 46 Chapter 5 Application of BenefitâCost Analysis for 3R Projects 46 5.1 Elements of BenefitâCost Analysis 53 5.2 Computational Examples of BenefitâCost Analysis 58 5.3 Interpreting Results of BenefitâCost Analysis 60 5.4 Using BenefitâCost Analysis to Establish Minimum AADT Guidelines for 3R Improvements 65 5.5 Specific Applications of BenefitâCost Analysis for Descriptions of 3R Project Design 67 5.6 BenefitâCost Analysis Tools 71 5.7 Application Examples Using the BenefitâCost Spreadsheet Tools C O N T E N T S
98 Chapter 6 3R Project Design Guidelines for Specific Roadway Types 98 6.1 Rural Two-Lane Highways 109 6.2 Rural Multilane Undivided Highways 114 6.3 Rural Multilane Divided Highways (Nonfreeways) 120 6.4 Urban and Suburban Arterials 122 6.5 Rural and Urban Freeways 125 Chapter 7 Summary of 3R Design Guidelines 128 Acronyms and Abbreviations 129 References 131 Appendix A Userâs Guide for Spreadsheet Tool 1 179 Appendix B Userâs Guide for Spreadsheet Tool 2 224 Appendix C Updated Crash Cost Estimates 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.