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TRANSPORTATION RESEARCH BOARD WASHINGTON, D.C. 2015 www.TRB.org 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 REPORT S2-S31-RW-3 Naturalistic Driving Study: Linking the Study Data to the Roadway Information Database Shane B. McLaughLin and Jonathan M. hankey Virginia Tech Transportation Institute Blacksburg, Virginia
Subject Areas Data and Information Technology Highways Safety and Human Factors Vehicles and Equipment
The Second Strategic Highway Research Program Americaâs highway system is critical to meeting the mobility and economic needs of local communities, regions, and the nation. Developments in research and technologyâsuch as advanced materials, communications technology, new data collection tech- nologies, and human factors scienceâoffer a new opportunity to improve the safety and reliability of this important national resource. Breakthrough resolution of significant transportation 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 Congestion, 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 com- plement 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 disruptions and produce lasting facilities; Reliability, to reduce congestion through incident reduction, management, response, and mitigation; and Capacity, to integrate mobility, economic, environmental, and community needs in the planning and designing of new trans- portation 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 memo- randum of understanding among the American Association 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. SHRP 2 Reports Available by subscription and through the TRB online bookstore: www.mytrb.org/store Contact the TRB Business Office: 202-334-3213 More information about SHRP 2: www.TRB.org/SHRP2 SHRP 2 Report S2-S31-RW-3 ISBN: 978-0-309-31493-0 Â© 2015 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. Permission is given with the understanding that none of the material will be used to imply TRB, AASHTO, or FHWA endorsement of a particular prod- uct, 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 âwâ 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 manufacturersâ names appear herein solely because they are considered essential to the object of the report.
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 Academyâs 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 Boardâs 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 Kenneth Campbell, Chief Program Officer for SHRP 2 Safety. James Hedlund, SHRP 2 Special Consultant for Safety Coordination, also contributed to the project. This project could not have been conducted without the help of many individuals at the Virginia Tech Transportation Institute. The authors would like to thank Brian Daily for his work tuning the database cluster to maximize throughput in this effort. Special thanks go to Keith Hangland from HERE; this project would never have happened without his efforts to hunt down an earlier version of HEREâs digital maps for use in this work. The authors would also like to thank Omar Smadi and Zach Hans of the Center for Transportation Research and Education for their guidance on the structure of the Roadway Information Database and on how they saw it being used. SHRP 2 STAFF Ann M. Brach, Director Stephen J. Andrle, Deputy Director Cynthia Allen, Editor Kenneth Campbell, Chief Program Officer, Safety Jared Cazel, Editorial Assistant 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 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 David Plazak, Senior Program Officer, Capacity and Reliability Rachel Taylor, Senior Editorial Assistant Dean Trackman, Managing Editor Connie Woldu, Administrative Coordinator
This report details the methodology used to link the second Strategic Highway Research Program (SHRP 2) Naturalistic Driving Study (NDS) data to the SHRP 2 Roadway Infor- mation Database (RID), the final critical step in completing the SHRP 2 Safety database. The NDS data set contains extensively detailed data collected continually from more than 5.5 million trips taken by the instrumented vehicles of 3,147 volunteer drivers in six sites. The RID contains extensively detailed data on 25,000 centerline miles of roadways in these six sites, less detailed data on 200,000 centerline miles of roadways in the six states in which the sites were located, and supplemental data on topics such as crash histories, travel vol- umes, construction, and weather in the six states. The true power of the NDS and the RID comes when they are linkedâwhen each trip is matched to the roadway segments that were traveled and each roadway segment is matched to the trips that traveled on it. The matching methodology documented in this report uses as input the GPS position data collected once per second by the NDS instrumentation and the NAVTEQ network of road segments of all public roads in the continental United States over which the NDS vehicles could travel. The Matching Algorithm associates each GPS point of an NDS trip with the road segment on which a vehicle traveled. The principal challenges overcome by the algorithm were to accommodate GPS readings that may drift far from the correct roadway and to be operationally efficient in comparing the 3.7 billion GPS readings with the 2.6 mil- lion NAVTEQ road segments that were traversed. The algorithmâs results are stored in a very large table that associates trip timestamps with road segments. The SHRP 2 NDS is the first large-scale study focused on collision prevention (as opposed to injury prevention once a collision occurs) since the Indiana Tri-Level Study (Tri-Level Study of the Causes of Traffic Accidents: Final Report, DOT HS-805 085, U.S. Department of Transportation, May 1979). Vehicle use was recorded continuously during the SHRP 2 NDS. Information on vehicle travel, or exposure, can be extracted at the same level of detail as for safety-related events, such as crashes and near crashes. Hence, the SHRP 2 NDS is the first large-scale study to support detailed estimates of collision risk. Moreover, crashes are a lead- ing cause of nonrecurring congestion, so collision prevention has added benefits in terms of reduced delay, fuel consumption, and emissions. The NDS provides objective information on the role of driver behavior and performance in traffic collisions and the interrelationship of the driver with vehicle, roadway, and environmental factors. The SHRP 2 Safety research program was carried out under the guidance of the Safety Technical Coordinating Committee (TCC), which was composed of volunteer experts. The Safety TCC developed and approved all project descriptions and budgets and met semi- annually to review progress and approve any program modifications. The Oversight Com- mittee approved all budget allocations and contract awards. Assistance was provided by expert task groups, which developed requests for proposals, evaluated proposals, recom- mended contractors, and provided expert guidance on many issues, such as data access policies and procedures. The decisions and recommendations of the governing committees are imple- mented by the SHRP 2 staff as they carry out day-to-day management of the research projects. F O R EWO R D Kenneth L. Campbell, SHRP 2 Chief Program Officer, Safety, and James Hedlund, SHRP 2 Special Consultant, Safety Coordination
C O N T E N T S 1 CHAPTER 1 Background 1 Overview 1 Previous Methods for Associating GPS Points with Roadways Using GIS-Based Tools 3 Improving the Methods 4 CHAPTER 2 Research Approach 4 Matching Process Methods 6 File Processing 12 CHAPTER 3 Findings and Applications 12 Linking Table 12 Linking Maps 12 Incident to Roadway Tables and Crash/Near-Crash Count Maps 13 Measures of Amount Matched 17 Sample Code and Instructional Materials 18 CHAPTER 4 Conclusions and Limitations 18 Limitations 19 References 20 Appendix A. SHRP 2 Manual Route Matching Protocol 24 Appendix B. Example of Visualizing File Counts on Links of Interest Using ArcGIS