Roadside Safety Analysis Program (RSAP) Update (2022)

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NCHRP Web-Only Document 319: Roadside Safety Analysis Program (RSAP) Update Malcolm H. Ray Christine E. Carrigan Chuck A. Plaxico Shaw-Pin Miaou T. Olaf Johnson RoadSafe LLC Canton, ME Conduct of Research Report for NCHRP Project 22-27 Submitted October 2012 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 transportation results in increasingly complex problems of wide interest to highway 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 initiated 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 Agreement No. 693JJ31950003. 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. DISCLAIMER The opinions and conclusions expressed or implied in this report are those of the researchers who performed the research. They are not necessarily those of the Transportation Research Board; the National Academies of Sciences, Engineering, and Medicine; the FHWA; or the program sponsors. The information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.

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 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. 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 WEB-ONLY DOCUMENT 319 Christopher J. Hedges, Director, Cooperative Research Programs Lori L. Sundstrom, Deputy Director, Cooperative Research Programs Waseem Dekelbab, Associate Program Manager, National Cooperative Highway Research Program David Jared, Senior Program Officer Traci Caldwell, Senior Program Assistant Natalie Barnes, Director of Publications Heather DiAngelis, Associate Director of Publications Jennifer J. Weeks, Publishing Projects Manager NCHRP PROJECT 22-27 PANEL Field of Design—Area of Vehicle Barrier Systems Carl M. Ochoa, Vista Engineering Services, Inc., Plano, TX (Chair) William H. Cook, Data Transfer Solutions, LLC, Orlando, FL Keith Cota, New Hampshire Department of Transportation, Concord, NH Rodney Erickson, Olympia, WA Dean A. Focke, Dublin, OH Randy Hiatt, California Department of Transportation (CALTRANS), Sacramento, CA Aurora Meza, VRX, Inc., Austin, TX Jeffrey Shaw, Federal Highway Administration (FHWA), Peru, IL Dean Sicking, University of Alabama, Birmingham, Birmingham, AL Catherine Satterfield, FHWA Liaison Stephen F. Maher, TRB Liaison

i Table of Contents List of Figures ................................................................................................................................. ii List of Tables .................................................................................................................................. ii INTRODUCTION .......................................................................................................................... 1 BACKGROUND ............................................................................................................................ 1 Encroachment Approach ............................................................................................................ 4 Rationale ................................................................................................................................. 5 Crash-Data Approach ................................................................................................................. 7 Highway Safety Manual ......................................................................................................... 8 Appropriate Use of Analysis Approaches .................................................................................. 8 RESULTS OF SURVEY OF PRACTICE ...................................................................................... 8 Question 1: Please provide the following optional information about yourself. ................... 9 Question 2: What type of work do you do? ........................................................................... 9 Question 3: Which highway design software tools does your company/organization use for design and plan production? ................................................................................................. 10 Question 4: Please list other software tools you use to assist with design decisions and cost analysis. ................................................................................................................................. 11 Question 5: The Roadside Safety Analysis Program (RSAP) has been developed for risk analysis and cost-benefit analysis of roadside safety and design. It is distributed with the Roadside Design Guide. How frequently do you use RSAP? ............................................. 11 Question 6: What have you used RSAP to evaluate? .......................................................... 11 Question 7: Do you like the RSAP user interface? .............................................................. 12 Question 8: Do you like RSAP functionalities? .................................................................. 12 Question 9: Do you find the RSAP default data tables appropriate? ................................... 13 Question 10: Do you like the RSAP methodology? ............................................................ 13 Question 11: Do you find the RSAP User's Manual helpful? .............................................. 14 Question 12: Do you find the Engineer's Manual helpful? .................................................. 14 Question 13: While using RSAP, have you encountered any incidents where your analysis results from RSAP were inconsistent with your experience/expectations/judgment? .......... 14 Question 14: Are you aware of reports or papers about RSAP documenting its use? Please list them here. ........................................................................................................................ 15 Question 15: What improvements would you like to see made to RSAP? .......................... 15 Question 16: Which features of RSAP would you like to see remain unchanged in the next release? .................................................................................................................................. 15

ii Question 17: Do you see value in integrating RSAP with popular highway design software tools such as AutoCAD Civil3D or Bentley InRoads? ......................................................... 16 Question 18: Do you see a potential use for evaluating the Cost/Benefit of roadside design alternatives using software integrated with your highway design software? ....................... 16 Question 19: Do you believe safety or the potential for crashes should be considered when designing highway improvements?....................................................................................... 16 Question 20: Thank you for your time. If you would like to be a beta tester for the RSAP upgrade, please list your contact information, including your e-mail, here. ........................ 16 Conclusions ........................................................................................................................... 16 PROGRAM OVERVIEW ............................................................................................................ 17 Background .............................................................................................................................. 17 Modeling Encroachments ......................................................................................................... 19 Modeling Crashes ..................................................................................................................... 19 Modeling Srash Severity .......................................................................................................... 20 Validation ................................................................................................................................. 20 RESEARCH NEEDS .................................................................................................................... 20 CONCLUSION ............................................................................................................................. 22 ACKNOWLEDGMENTS ............................................................................................................ 23 REFERENCES ............................................................................................................................. 24 The following appendices are available on the National Academies Press website (www.nap.edu) by searching for NCHRP Web-Only Document 319: Roadside Safety Analysis Program (RSAP) Update. Appendix A: RSAPv3 User's Manual Appendix B: RSAPv3 Engineer's Manual Appendix C: RSAPv3 Programmer’s Manual Appendix D: Survey Form and Results LIST OF FIGURES Figure 1. Distribution of Respondents’ Work Categories. .......................................................... 10 Figure 2. Distribution of CAD Software Use. ............................................................................. 11 LIST OF TABLES Table 1. Comparison of RSAP and ROADSIDE. [after Mak03] ................................................ 18