Intersection Crash Prediction Methods for the Highway Safety Manual

Research is needed to expand the range of intersection types addressed in the predictive methods in Chapters 10, 11, and 12 of the AASHTO Highway Safety Manual (HSM). These methods address many of the more common intersection configurations and traffic control types, but there are many configurations that still need to be addressed to maximize the utility of the HSM. Intersection types where crashes are more likely should be given priority to be thoroughly addressed. Moreover, the existing methods do not include the ability to predict the change in the fatality and severity distribution as a result of a change in the intersection’s design or traffic control features. Some examples of intersection configurations and traffic control modes that are not currently addressed in the HSM include: intersections with all-way stop control, intersections on high-speed expressways, three-leg intersections on rural highways with signal control, three-leg intersections with a commercial driveway forming a fourth leg, and five-leg intersections. The intersection at a single-point diamond interchange is also not currently addressed. Additionally, the methods do not currently address the crash frequency and severity distribution for intersections located on or near horizontal and vertical curves. Recent research indicates that rural intersection safety is negatively affected by wide medians in higher volume conditions, but positively affected by wide medians in lower volume conditions. This sensitivity is not included in the current HSM predictive methods for intersections. The method should provide information useful to the planning and design of streets and highways and should be sensitive to a wide range of intersection design elements and traffic control features. The objective of the research is to develop a set of crash predictive models consistent with existing methods that are comprehensive in their ability to address a wide range of intersection configurations and traffic control modes in rural and urban areas. The focus should be to: (1) address intersection configurations and traffic control types not currently addressed in the HSM and (2) develop supplemental models for predicting the severity distribution as a function of geometric design elements and traffic control features. The predictive models developed in this research are to include safety performance functions (SPFs), crash modification factors (CMFs), and calibration factors in a format that is consistent with the predictive models in the existing HSM Part C. The predictive models should be sensitive to the traffic volumes on all intersecting roads and streets, design elements, and traffic control features considered by engineers and planners during the project development process. The research results are intended for possible inclusion in a future edition of the HSM. Roundabouts shall not be addressed in this research.


  • English


  • Status: Active
  • Funding: $600000
  • Contract Numbers:

    Project 17-68

  • Sponsor Organizations:

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590

    American Association of State Highway & Transportation Officials (AASHTO)

    444 North Capitol Street, NW, Suite 225
    Washington, DC  United States  20001

    National Cooperative Highway Research Program

    Transportation Research Board
    500 Fifth Street, NW
    Washington, DC  United States  20001
  • Project Managers:

    Bush, Mark

  • Performing Organizations:

    MRI Global

  • Principal Investigators:

    Torbic, Darren

  • Start Date: 20140901
  • Expected Completion Date: 20181031
  • Actual Completion Date: 0
  • Source Data: RiP Project 37700

Subject/Index Terms

Filing Info

  • Accession Number: 01543623
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 17-68
  • Files: TRB, RiP
  • Created Date: Nov 19 2014 1:03AM