Practical Approaches to Quantifying Safe System Concepts

The use of Safe System principles for roadway design and operations is showing significant success worldwide in reducing fatal and serious crashes for all road users, including those who walk and bike. The Safe System approach recognizes that all road users should be treated equitably, in a manner that considers safety tradeoffs for all, and that death and serious injury are preventable when consideration is given to the tolerance of the human body to crash forces. In addition, the Safe System approach applies to all roadways: urban or rural, and under state, local or tribal jurisdiction. Finally, the Safe System approach recognizes that human errors occur and that by designing and operating road infrastructure to account for these errors crash likelihood is reduced. Searching for opportunities to reverse the upward trend in traffic fatalities, many state departments of transportation (DOTs) are interested in moving towards a Safe System approach and have been looking at practical ways to reduce crash forces at intersections and roadways. In some cases, this has resulted in the development of policy changes in speed management and design directives. The objective of this research is to investigate the correlation between a Safe System for Intersections (SSI) score and observed fatal and serious injury crash frequency at an intersection so that a benefit/cost ratio or cost effectiveness associated with the SSI score can be determined. This methodology then can be applied to corresponding roadway segments. The research will also recommend how the SSI can be adopted to design and operational criteria for future implementation. Pilot testing of the research results will be used to validate and strengthen the methodology and will provide additional knowledge to those transportation agencies implementing the new model. This research will help safety professionals more fully understand the relationships between economic, regulatory, vehicle, and infrastructure factors and traffic fatalities and the mechanisms by which they operate to provide state DOTs with insights that can be used to target fatality reduction programs and projects. Moreover, strategies that combine domains will be important for using state resources efficiently to maximize fatality reductions.


  • English


  • Status: Proposed
  • Funding: $450000
  • Contract Numbers:

    Project 17-116

  • Sponsor Organizations:

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001

    American Association of State Highway and Transportation Officials (AASHTO)

    444 North Capitol Street, NW
    Washington, DC  United States  20001

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Project Managers:

    Jared, David

  • Start Date: 20220607
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01845586
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 17-116
  • Files: TRB, RIP
  • Created Date: May 18 2022 10:44AM