A Safe System-Based Framework and Analytical Methodology for Assessing Intersections

This report presents a Safe System for Intersections (SSI) method that intersection planners and designers can readily implement, that dovetails with the typical U.S. project development process, and that uses commonly available project-level data. The SSI method is presented in the context of a Stage 1 Intersection Control Evaluation (ICE), at the scoping phase of project development where intersection alternatives are analyzed with respect to whether they meet project needs and are practical to pursue. The method incorporates concepts of conflict point identification and classification, exposure, kinetic energy transfer, conflict point severity, and intersection movement complexity. Application of the SSI method results in multiple measures of effectiveness (MOEs) and a set of SSI scores that characterize the extent to which an intersection alternative in a given context aligns with the principles of kinetic energy management and a Safe System. The SSI MOEs and SSI scores can serve as additional safety metrics to inform the process of screening alternatives and identifying an optimal solution for an intersection. The report includes an overview of Safe System concepts and principles, a detailed description of the SSI method, example project applications, and a future vision for the method.

• Record URL:
  https://safety.fhwa.dot.gov/intersection/ssi/fhwasa21008.pdf
• Record URL:
  https://rosap.ntl.bts.gov/view/dot/58029
• Summary URL:
  https://rosap.ntl.bts.gov/view/dot/67035
• Corporate Authors:

  Vanasse Hangen Brustlin, Inc.

  ,    

  Federal Highway Administration

  Office of Safety
  1200 New Jersey Avenue SE
  Washington, DC  United States  20590
• Authors:
  • Porter, R J
  • Dunn, Michael
  • Soika, Jonathan
  • Huang, Ivy
  • Coley, Dylan
  • Gross, Annette
  • Kumfer, Wes
  • Heiny, Stephen
• Publication Date: 2021-1

Language

• English

Media Info

• Media Type: Digital/other
• Edition: Final Report
• Features: Appendices; Figures; References; Tables;
• Pagination: 159p

Subject/Index Terms

• TRT Terms: Evaluation and assessment; Highway safety; Highway traffic control systems; Intersections; Programming (Planning); Traffic conflicts
• Identifier Terms: Safe System
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; Safety and Human Factors;

Filing Info

• Accession Number: 01780562
• Record Type: Publication
• Report/Paper Numbers: FHWA-SA-21-008
• Contract Numbers: DTFH61-05-D-00024 (VHB)
• Files: NTL, TRIS, ATRI, USDOT
• Created Date: Aug 27 2021 2:58PM