Measures of Safety from Simulation Models

Every year in the U.S. more than 40,000 people are killed, hundreds of thousands of people are injured, and Billions of dollars are wasted in repairing vehicles and people resulting from traffic crashes on the nation’s street and highway network. Engineers and planners are constantly searching for new and innovative ways to improve traffic safety through road design, new types of traffic signs, signal control strategies, and other methods. Safety of traffic facilities is most often measured by counting the number (and severity) of crashes that occur. It is not possible to apply such a measurement technique to traffic facility designs that have not yet been built or deployed in the real world. This project for FHWA has resulted in the development of a methodology and software tool for deriving surrogate measures of safety of traffic facilities from data output by traffic simulation models. This method has been denoted the surrogate safety assessment model (SSAM). The surrogate measures developed in this project are based on the identification, classification, and evaluation of traffic conflicts that occur in the simulation model. Conflict events can be categorized based on the type of driving maneuver (crossing, rear-end, and lane-change events) and by several measures of severity of the event. This information, along with the location of the conflict, can provide insight into the relative safety of two intersection designs by running the simulation models with the same underlying traffic demand profile (i.e. common random numbers).

  • Corporate Authors:

    Institute of Transportation Engineers (ITE)

    Washington, DC  United States 

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Authors:
    • Gettman, Douglas
  • Conference:
  • Publication Date: 2008


  • English

Media Info

  • Media Type: CD-ROM
  • Features: Figures; Tables;
  • Pagination: 5p
  • Monograph Title: Compendium of Technical Papers. ITE 2008 Technical Conference and Exhibit, March 30-April 2, 2008, Miami, Florida

Subject/Index Terms

Filing Info

  • Accession Number: 01109035
  • Record Type: Publication
  • Files: TRIS, USDOT
  • Created Date: Aug 22 2008 8:42AM