Understanding the Contributions of Operations, Technology, and Design to Meeting Highway Capacity Needs (2012)

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The Second S T R A T E G I C H I G H W A Y R E S E A R C H P R O G R A M TRANSPORTATION RESEARCH BOARD WASHINGTON, D.C. 2014 www.TRB.org REPORT S2-C05-RW-1 Understanding the Contributions of Operations, Technology, and Design to Meeting Highway Capacity Needs Kittelson & AssociAtes, inc. in association with institute for trAnsportAtion reseArch And educAtion Ruhr University Bochum University of UtAh

Subject Areas Highways Operations and Traffic Management Planning and Forecasting

SHRP 2 Reports Available by subscription and through the TRB online bookstore: www.TRB.org/bookstore Contact the TRB Business Office: 202-334-3213 More information about SHRP 2: www.TRB.org/SHRP2 SHRP 2 Report S2-C05-RW-1 ISBN: 978-0-309-12929-9 © 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 copy- right to any previously published or copyrighted material used herein. The second Strategic Highway Research Program grants permission to repro- duce material in this publication for classroom and not-for-profit purposes. Per- mission is given with the understanding that none of the material will be used to imply TRB, AASHTO, or FHWA endorsement of a particular product, method, or practice. It is expected that those reproducing material in this document for educational and not-for-profit purposes will give appropriate acknowledgment of the source of any reprinted or reproduced material. For other uses of the material, request permission from SHRP 2. Note: SHRP 2 report numbers convey the program, focus area, project number, and publication format. Report numbers ending in “w” are published as web documents only. Notice The project that is the subject of this report was a part of the second Strategic 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 committee selected to monitor this project and review this report were chosen for their special competencies and with regard for appropriate balance. The report was reviewed by the technical committee 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 second Strategic Highway Research Program do not endorse products or manufacturers. Trade or manufacturers’ names appear herein solely because they are considered essential to the object of the report. The Second Strategic Highway Research Program America’s highway system is critical to meeting the mobility and economic needs of local communities, regions, and the nation. Developments in research and technology—such as advanced materials, communications technology, new data collection technologies, and human factors science—offer a new oppor- tunity to improve the safety and reliability of this important national resource. Breakthrough resolution of significant trans- portation problems, however, requires concentrated resources over a short time frame. Reflecting this need, the second Strategic Highway Research Program (SHRP 2) has an intense, large-scale focus, integrates multiple fields of research and technology, and is fundamentally different from the broad, mission-oriented, discipline-based research programs that have been the mainstay of the highway research industry for half a century. The need for SHRP 2 was identified in TRB Special Report 260: Strategic Highway Research: Saving Lives, Reducing Conges- tion, Improving Quality of Life, published in 2001 and based on a study sponsored by Congress through the Transportation Equity Act for the 21st Century (TEA-21). SHRP 2, modeled after the first Strategic Highway Research Program, is a focused, time- constrained, management-driven program designed to comple- ment existing highway research programs. SHRP 2 focuses on applied research in four areas: Safety, to prevent or reduce the severity of highway crashes by understanding driver behavior; Renewal, to address the aging infrastructure through rapid design and construction methods that cause minimal disrup- tions and produce lasting facilities; Reliability, to reduce conges- tion through incident reduction, management, response, and mitigation; and Capacity, to integrate mobility, economic, envi- ronmental, and community needs in the planning and designing of new transportation capacity. SHRP 2 was authorized in August 2005 as part of the Safe, Accountable, Flexible, Efficient Transportation Equity Act: A Legacy for Users (SAFETEA-LU). The program is managed by the Transportation Research Board (TRB) on behalf of the National Research Council (NRC). SHRP 2 is conducted under a memorandum of understanding among the American Associa- tion of State Highway and Transportation Officials (AASHTO), the Federal Highway Administration (FHWA), and the National Academy of Sciences, parent organization of TRB and NRC. The program provides for competitive, merit-based selection of research contractors; independent research project oversight; and dissemination of research results.

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 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 achieve- ments of engineers. Dr. C. D. (Dan) 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. Victor J. Dzau 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 Academy’s 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. (Dan) 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 Transportation Research Board is to provide leadership in transportation innovation and progress through research and information exchange, conducted within a setting that is objective, interdisci- plinary, and multimodal. The Board’s 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 Transporta- tion, and other organizations and individuals interested in the development of transportation. www.TRB.org www.national-academies.org

ACKNOWLEDGMENTS This work was sponsored by the Federal Highway Administration in cooperation with the American Asso- ciation of State Highway and Transportation Officials. It was conducted in the second Strategic Highway Research Program (SHRP 2), which is administered by the Transportation Research Board of the National Academies. The project was managed by Stephen Andrle, Deputy Director for SHRP 2. The authors thank the other members of the research team, whose contributions and insights made this research project possible. SHRP 2 STAff Ann M. Brach, Director Stephen J. Andrle, Deputy Director Neil J. Pedersen, Deputy Director, Implementation and Communications Cynthia Allen, Editor Kenneth Campbell, Chief Program Officer, Safety JoAnn Coleman, Senior Program Assistant, Capacity and Reliability Eduardo Cusicanqui, Financial Officer Richard Deering, Special Consultant, Safety Data Phase 1 Planning Shantia Douglas, Senior Financial Assistant Charles Fay, Senior Program Officer, Safety Carol Ford, Senior Program Assistant, Renewal and Safety Jo Allen Gause, Senior Program Officer, Capacity James Hedlund, Special Consultant, Safety Coordination Alyssa Hernandez, Reports Coordinator Ralph Hessian, Special Consultant, Capacity and Reliability Andy Horosko, Special Consultant, Safety Field Data Collection William Hyman, Senior Program Officer, Reliability Linda Mason, Communications Officer Reena Mathews, Senior Program Officer, Capacity and Reliability Matthew Miller, Program Officer, Capacity and Reliability Michael Miller, Senior Program Assistant, Capacity and Reliability David Plazak, Senior Program Officer, Capacity and Reliability Rachel Taylor, Senior Editorial Assistant Dean Trackman, Managing Editor Connie Woldu, Administrative Coordinator

F O R EWO R D Stephen J. Andrle, SHRP 2 Deputy Director Adding transportation capacity improves safety, accessibility, and the economic health of a region but often comes with an economic, social, or environmental price. The public is aware of the price and must be convinced that new capacity is really needed before they will support expansion. This implies that operational improvements to the roadway may be warranted to improve efficiency some years before a major capacity expansion is proposed. This report addresses the question, What gains in sustainable flow can be obtained from operational improvements to roadways? The report uses the term sustainable flow rather than capacity, to avoid confusion with other definitions of capacity. The researchers used enhanced simulation methods and network diagnostics, including travel time and travel time reliability, to test various types of operational improvements. This report will be of interest to traffic engineers, freeway managers, roadway designers, and transportation planners. This report builds on an emerging body of literature that suggests capacity is not a constant value but is a variable. Capacity (or sustainable flow) depends on driving behavior, the com- position of the drivers at the moment, driver familiarity with the roadway, the mix of vehicle types, trip purposes, weather, signalization, and the presence of upstream or downstream bottlenecks. Therefore, if operational improvements are made to a roadway, the sustain- able flow will be influenced by these variables. The research also suggests that the success of operational improvements in increasing sustainable flow is partially dependent on the configuration of the roadway network. The same effect is not necessarily achieved with every application. Finally, drivers learn and adapt to new roadway configurations. To properly analyze the effect of an operational improvement, this learning behavior should be recog- nized. The implication of these contextual factors is that simulation methods are needed to estimate the increase in sustainable throughput achieved from a package of operational improvements. The researchers added capabilities to existing simulation models to reflect the stochastic nature of capacity for freeways and arterials and day-to-day learning in the route selection algorithms. They also used link, corridor, and network diagnostic features for evaluation of alternatives and to identify locations on the network where the benefits of implementing operational strategies appear high. The researchers evaluated emerging technologies and network operations treatments, from which they selected 25 for testing, including actions such as ramp metering, inter- change modification, queue management, narrow lanes, adaptive signals, and pretrip infor- mation. A simulation modeling approach was used to test strategies on networks and data from Fort Worth, Texas, and Portland, Oregon.

The results of applying the simulation techniques to the various strategies indicate the following: • Multiple performance measures are needed to obtain a complete assessment. • Measures should reflect link, corridor, and network characteristics. • Driver’s route choice must be considered to analyze network-level effects. • A representative cross section of corridors and O-D pairs should be evaluated. • The effectiveness of a particular operational improvement can only be evaluated in context. • The reliability of travel times may improve even when the actual travel time remains unchanged. The report describes the simulation modeling framework and the equations used for the enhancing simulation software.

C O N T E N T S 1 Executive Summary 2 Strategies Selected for Testing 2 Network Operations Modeling Approach 7 Baseline Models 7 Strategy Testing 10 Model Portability Considerations 10 Conclusions and Next Steps 11 References 12 CHAPTER 1 Introduction 12 Project Background 13 References 14 CHAPTER 2 Analytic Enhancements to Enable Network Assessment of Strategies 14 Summary of Key Findings and Conclusions 14 Overall Modeling Framework 16 Enhancement 1: Stochastic Capacity for Freeway Bottlenecks 25 Enhancement 2: Stochastic Capacity and Turn Pocket Analysis on Arterials 29 Enhancement 3: Implementation of Day-to-Day Learning Paradigm 32 Enhancement 4: New Performance Measures and Implementation Considerations 36 References 37 CHAPTER 3 Operational Technologies and Treatments 37 Key Findings and Conclusions 37 Technologies Affecting Traffic Operations 46 Inventory of Network Operations Treatments 51 References 52 CHAPTER 4 Strategy Testing Results and Insights 53 Individual Strategy Testing: Fort Worth Network 67 Illustrative Application of Methods, Metrics, and Strategies 78 Reference 79 CHAPTER 5 Next Steps 79 Accounting for the Effects of Nonrecurring Congestion 79 Approach 80 Suggested Work Plan 81 Appendix A. Supplemental Materials for Uninterrupted Flow Facilities