Applying the Safe System Approach to Transportation Planning, Design, and Operations (2025)
Chapter: Front Matter
Applying the Safe System Approach to Transportation Planning, Design, and Operations
The University of North Carolina Highway Safety Research Center
Chapel Hill, NC
Burgess & Niple
Columbus, OH
Mobycon
Ottawa, Ontario, Canada
UC-Berkeley SafeTREC
Berkeley, CA
Kelvin Grove
Centre for Accident Research and Road Safety
Queensland, Australia
Timothy E. Barnett
Troy, AL
Alan Dellapenna
Wake Forest, NC
Conduct of Research Report for NCHRP Project 17-101
Submitted August 2024
NCHRP Web-Only Document 413
Applying the Safe System Approach to Transportation Planning, Design, and Operations
© 2025 by the National Academy of Sciences. National Academies of Sciences, Engineering, and Medicine and the graphical logo are trademarks of the National Academy of Sciences. All rights reserved.
Digital Object Identifier: 10.17226/29148
NATIONAL COOPERATIVE HIGHWAY RESEARCH PROGRAM
Systematic, well-designed, and implementable research is the most effective way to solve many problems facing state department of transportation (DOT) 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.
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The National Academy of Sciences (NAS) grants permission to reproduce written material in this publication for classroom and non-commercial purposes subject to the rights of any third parties and appropriate attribution. Permission is given with the understanding that none of the material will be used to imply NAS, TRB, AASHTO, APTA, FAA, FHWA, FTA, GHSA, or NHTSA endorsement of a particular product, method, or practice. For other uses of the written material, users must request permission from the National Academies Press.
DISCLAIMER
This material is based upon work supported by the FHWA under Agreement No. 693JJ32350025. Any opinions, findings, and conclusions or recommendations expressed or implied in this document 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 specifications. 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, and the sponsors of the National Cooperative 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 information contained in this document was taken directly from the submission of the author(s). This material has not been edited by TRB.
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Learn more about the Transportation Research Board at www.TRB.org.
COOPERATIVE RESEARCH PROGRAMS
CRP STAFF FOR NCHRP WEB-ONLY DOCUMENT 413
Monique R. Evans, Director, Cooperative Research Programs
Waseem Dekelbab, Deputy Director, Cooperative Research Programs, and Manager, National Cooperative Highway Research Program
David M. Jared, Senior Program Officer
Dajaih Bias-Johnson, Senior Program Assistant
Natalie Barnes, Director of Publications
Heather DiAngelis, Associate Director of Publications
Kristin C. Sawyer, Editor
Jennifer Correro, Assistant Editor
NCHRP PROJECT 17-101 PANEL
Field of Traffic—Area of Safety
Bonnie S. Polin, Massachusetts Department of Transportation, Boston, MA (Chair)
Angshuman Guin, Georgia Institute of Technology, Atlanta, GA
Susan B. Herbel, SBH Consult, Fort Meyers, FL
Margaret Mary Herrera, Maricopa Association of Governments, Phoenix, AZ
Ken Johnson, Minnesota Department of Transportation, Roseville, MN
Daniel J. Magri, Buchart Horn, Inc., Baton Rouge, LA
Mark A. Doctor, FHWA Liaison
Kelly K. Hardy, AASHTO Liaison
Bernardo B. Kleiner, TRB Liaison
AUTHOR ACKNOWLEDGMENTS
The authors acknowledge the respondents to the research team’s practitioner survey and the focus group participants. The insights provided by the survey respondents and focus group participants rendered the guidance provided herein far more practical and useful than had they not contributed to this effort.
Contents
Background: Defining the Safe System
Safe System Principles and Pillars (Elements/Outcomes)
Safe System Pillars (Elements/Outcomes)
Safe System Implementation Framework
System Operator Responsibility
Safe System Practice Extraction
Survey Development and Measures
All Safety Practice Rankings (listed from most feasible and impactful to least)
Practical Implications for Guidance
Appendix A: Practitioner Survey
Appendix B. Focus Group Protocol
NCHRP Web-Only Document 413 contains the conduct of research report for NCHRP Project 17-101 and accompanies NCHRP Research Report 1135: A Guide to Applying the Safe System Approach to Transportation Planning, Design, and Operations. Readers can read or purchase NCHRP Research Report 1135 on the National Academies Press website (nap.nationalacademies.org).
List of Figures
Figure 1. Location of Survey Respondents.
List of Tables
Table 1. Proposed Organization Principles.
Table 2. Respondents’ primary professional roles.
Table 3. Respondents’ professional tenure in their professional field.
Table 4. Factor loadings of each of the organizational climate constructs.
Table 5. Correlations among Innovativeness, Individualism, and Fatalism constructs.
Table 6. Linear regression results.
Table 7. Opinion leading professionals according to survey respondents.
Table 8. Interpretive categorization of Z-scores, with a mean of 0 and standard deviation of 1.
Table 9. Top two most feasible and impactful safety practices.
Table 10. Top two practices perceived as the most impactful regardless of their feasibility.
Table 11. Diverse professionals’ perspectives on cross-domain safety practices.
Table 12. Policy practice feasibility and impact scores.
Table 13. Planning practice feasibility and impact scores.
Table 14. Design practice feasibility and impact scores.
Table 15. Operations and Maintenance practice feasibility and impact scores.
Table 16. Enforcement practice feasibility and impact scores.
Table 17. Post-Crash Response practice feasibility and impact scores.
