Roadway Cross-Section Reallocation: A Guide (2023)

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2023 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 1036 Roadway Cross-Section Reallocation A GUIDE Conor Semler Meredyth Sanders Camilla Dartnell Mike Alston Sophia Semensky Laura Ahramjian Katie Taylor Kittelson & Associates, Inc. Boston, MA Rebecca Sanders Safe Streets Research & Consulting Portland, OR Mary Elbech Zach Vanderkooy Mobycon Durham, NC North Carolina State University Institute for Transportation Research and Education Raleigh, NC Subscriber Categories Highways • Pedestrians and Bicyclists • Public Transportation Research sponsored by the American Association of State Highway and Transportation Ofcials 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 techniques—the 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 TRB’s 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; TRB’s 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&I’s 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 1036 Project 15-78 ISSN 2572-3766 (Print) ISSN 2572-3774 (Online) ISBN 978-0-309-69891-7 Library of Congress Control Number 2023941937 © 2023 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trade- marks of the 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, APTA, FAA, FHWA, FTA, GHSA, or NHTSA 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 photo: Radu Nan/Kittelson & Associates, Inc. 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 does not develop, issue, or publish standards or spec- ifications. The Transportation Research Board manages applied research projects which provide the scientific foundation that may be used by Transportation Research Board sponsors, industry associations, or other organizations as the basis for revised practices, procedures, or specifications. 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. 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e 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. e 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. e 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. e 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. e 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. e Transportation Research Board is one of seven major programs of the National Academies of Sciences, Engineering, and Medicine. e 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. e Board’s 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. e 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 DEDICATION The authors would like to pay tribute to Jeremy Fletcher. Jeremy was an important contributor on the NCHRP Project 15-78 Panel and had an enormous impact on our research. His perspective challenged us and guided the development of our work. At team meetings, we would frequently ask ourselves, “What would Jeremy think?” to evaluate a new idea. His commitment to the research and candid feedback made our products better. CRP STAFF FOR NCHRP RESEARCH REPORT 1036 Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program Dianne S. Schwager, Senior Program Officer Dajaih Bias-Johnson, Senior Program Assistant Natalie Barnes, Director of Publications Heather DiAngelis, Associate Director of Publications Hilary Freer, Senior Editor NCHRP PROJECT 15-78 PANEL Field of Design—Area of General Design Celeste A. Gilman, Washington State Department of Transportation, Seattle, WA (Chair) Al Beatty, CALSTART, Philadelphia, PA Antonette C. Clark, California Department of Transportation, Sacramento, CA Michelle L. Danila, Toole Design, Boston, MA Nnenna April Eke, Walter P Moore, Dallas, TX Jeremy W. Fletcher, Florida Department of Transportation, Tallahassee, FL (Deceased) Karla J. Kingsley, City of Portland Bureau of Transportation, Portland, OR Peter Ohlms, Virginia Department of Transportation, Charlottesville, VA Elizabeth Hilton, FHWA Liaison Clayton Wellman, FHWA Liaison Patricia Bush, AASHTO Liaison

AUTHOR ACKNOWLEDGMENTS This Guide was developed under NCHRP Project 15-78 by Kittelson & Associates, Inc., with the support of Safe Streets Research & Consulting, Mobycon, and the North Carolina State University Institute for Trans- portation Research and Education (ITRE). Conor Semler of Kittelson & Associates, Inc., was the principal investigator. Meredyth Sanders was instrumental throughout the research and in the Guide development process, leading the case study synthesis, framework development, and agency peer exchange. She wrote several chapters, including the section on overcoming barriers to safe street design. Mike Alston and Sophia Semensky developed the Decision-Making Framework Spreadsheet Tool. Camilla Dartnell and Mike Alston developed the decision support matrix, compiling research to help predict outcomes of cross- section decisions. Camilla Dartnell summarized this research in the cross-section elements section of the Guide. Laura Ahramjian led the chapter on opportunities to change cross sections. Katie Taylor supported the development of the Guide with technical writing and editing and helped craft the Guide’s overall tone and style. Figures and graphics were created by Helen Regan, Olga Vairo, and Susan Mah. Bastian Schroeder, Hermanus Steyn, Mary Raulerson, and Paul Ryus provided guidance and direction to the research team and careful review and support in the development of the Guide. Rebecca Sanders of Safe Streets Research & Consulting provided support throughout the project, including the development of the pedestrian safety guidance and planning context chapter in the Guide. Mary Elbech of Mobycon, supported by Zach Vanderkooy, led the international literature and best practices review and led the safety section of the Guide. Justin Goulding developed the bicycle safety guidance. Ishtiak Ahmed and Chase Nicholas of ITRE, supported by Christopher Cunningham, led the analysis of the case study data. Sarah Searcy and Steve Bert helped guide the direction of the research in the early phases and helped identify and execute the case studies. The research team thanks the numerous organizations and persons who participated in the project’s outreach efforts, including the agency peer exchange meetings and the detailed case studies.

This Guide is a first-of-its-kind resource for transportation practitioners planning to redesign urban and suburban streets in a manner that reflects community needs and inter- ests. It features a framework for how transportation agencies can make informed decisions when reallocating space and will help transportation practitioners answer the question: what happens when we reallocate roadway space in urban and suburban areas? The Guide integrates transparency into the decision-making process, helping practitioners compare tradeoffs and facilitate productive community conversations regarding who gets to use roadway space and how they can use it. The tradeoffs affect a community’s mobility, safety, economy, and quality of life. This Guide will be of immediate use to transportation professionals, decision- makers, and the community. The centerpiece of this Guide is the Decision-Making Framework that provides a process for developing cross sections based on community priorities, mobility needs, and trans- portation safety. Whatever a community prioritizes—equity, environment, local economy, or even parking—this Guide can help tie those goals to roadway cross-section decisions. The framework presents a stepwise process that walks practitioners through the questions they will need to answer to select a cross section that suits its context and the needs of its users. Since cross-section decisions are fundamentally dimensional, the framework draws on best practice in street design to recommend minimum dimensions for each street component to develop cross sections that provide streets that are safe for all intended roadway users. Focusing on urban and suburban land use contexts, this project compiled the information available from research on the transportation and non-transportation outcomes associ- ated with changes to streets. The Guide includes two spreadsheet tools—one for resurfacing projects and one for reconstruction projects—to help practitioners implement the decision- making framework. The research included three major components: • A comprehensive literature review that categorized existing research related to roadway design tradeoffs and associated impacts for (1) roadway reallocation, (2) prioritization and process, and (3) the operational and non-transportation outcomes associated with multimodal cross-section design elements. • A series of peer exchange meetings with practitioners and decisionmakers to understand opportunities for and barriers to cross-section reallocation. The peer exchange served to fill holes and knowledge gaps in the published state of practice. • Ten case studies drawing insights from examples across a wide range of urban and suburban contexts. The case studies answered the following questions: (1) What are the operational F O R E W O R D By Dianne S. Schwager Staff Officer Transportation Research Board

and safety effects on each travel mode when motor vehicle speeds are reduced because of a roadway reallocation? (2) What are the travel time effects by mode of reducing motor vehicle speeds in an intersection-heavy environment? (3) Where does traffic go when lanes are reallocated from automobile to non-automobile modes? Does it divert to other streets? Does it evaporate? By how much? (4) What are the impacts of roadway reallocation projects on adjacent businesses? To support the development of the decision-making framework and spreadsheet tools, the research team compiled best practices for street dimensions based on roadway and land use context. This information is embedded into the Decision-Making Tools and is presented in the Guide along with each cross-section element in a graphical look-up table. Under NCHRP Project 15-78, “Guidebook for Urban and Suburban Roadway Cross- Sectional Reallocation,” Kittelson & Associates was asked to develop a guidebook and decision- making framework for roadway designers, planners, and others for identifying, comparing, evaluating, and justifying context-based cross-section reallocations of existing urban and sub- urban roadway space for multimodal safety, access, and mobility. This report is supplemented by the following tools for practitioners: • Decision-Making Spreadsheet Tool – Reconstruction • Decision-Making Spreadsheet Tool – Repaving • Decision Support Excel Matrix • Infographic that presents the cross-section decision-making framework In addition, NCHRP Web-Only Document 342: Roadway Cross-Section Reallocation: Conduct of Research Report is available for download the National Academies Press website (nap.nationalacademies.org) by searching for NCHRP Web-Only Document 342.

S-1 Summary 1-1 Chapter 1 Introduction 1-1 A Safety-First Approach to Allocating Roadway Space 1-1 The Changing Paradigm 1-2 Understanding the Tradeoffs 1-2 Communicating Clearly About Vehicle Lane Removal 1-3 Raising the Floor on Safety 1-3 Making Decision-Making Transparent 1-3 Connecting Decisions to Outcomes 1-4 Using This Guide 2-1 Chapter 2 Choosing a Roadway Cross Section That Serves Your Vision 2-1 Decision-Making Principles 2-1 Decision-Making Process 3-1 Chapter 3 Opportunities to Change a Cross Section 3-1 Define Your Limits 3-1 Determine Your Project Type 3-3 Additional Considerations 3-9 Prioritize Safety 4-1 Chapter 4 Planning Context 4-1 Set Your Goals 4-1 Transportation Policies and Goals 4-4 Indirect Transportation Policies and Goals 4-6 Summary 5-1 Chapter 5 Safety for Everyone 5-1 Making Street Functions Clear 5-3 Benefits of a Network Plan and Clearly Articulated Street Function 5-4 Managing Speeds for Safety 5-5 Absolute Risk Versus Exposure 5-5 How a Safe System Approach Puts Safety First 5-6 Applying a Safe System Approach 5-12 Speed and Street Type Matter 5-12 Summary 6-1 Chapter 6 Overcoming Barriers to Safe Design 6-1 Geometric/Physical Constraints 6-9 Stakeholder and User Concerns 6-15 Limited Resources 6-16 Summary C O N T E N T S

7-1 Chapter 7 Cross-Section Elements 7-1 What Happens When You Change Your Cross Section? 7-1 Cross-Section Makeup 7-20 Summary 8-1 Chapter 8 Making and Evaluating Cross-Section Changes 8-1 Making Changes, Measuring Their Effects 8-1 The Role of Funding 8-2 Design and Construction 8-4 Evaluating the New Design 8-7 Engaging Agency Partners, Decisionmakers, and Community Members 8-11 Case Studies 8-19 Summary 9-1 Chapter 9 Conclusions R-1 References and Bibliography G-1 Glossary A-1 Appendix A Cross-Section Decision-Making Tool and User Guide B-1 Appendix B Decision Support Matrix C-1 Appendix C Applying the Framework