Updating Safety Performance Functions for Data-Driven Safety Analysis

The objectives of this research were to (1) determine how frequently Safety Performance Factors (SPFs), SPF adjustment factors (also called Crash Modification Factors (CMFs) in Part C of the Highway Safety Manual), and Severity Distribution Functions (SDFs) should be updated; (2) determine under what conditions (e.g., changes in data and statistical properties) that SPFs, SPF adjustment factors, and SDFs require updates; and (3) develop an implementable approach and guidance for maintaining and updating existing and future functions and factors.


  • English


  • Status: Completed
  • Funding: $500000
  • Contract Numbers:

    Project 17-93

  • Sponsor Organizations:

    American Association of State Highway and Transportation Officials (AASHTO)

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

    National Cooperative Highway Research Program

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

    Federal Highway Administration

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

    Dekelbab, Waseem

  • Performing Organizations:

    University of North Carolina at Chapel Hill

    UNC-CH New East Building
    Campus Box #3140
    Chapel Hill, North Carolina  United States  27599-3140
  • Principal Investigators:

    Srinivasan, Raghavan

  • Start Date: 20190701
  • Expected Completion Date: 20221231
  • Actual Completion Date: 20221231

Subject/Index Terms

Filing Info

  • Accession Number: 01672554
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 17-93
  • Files: TRB, RIP
  • Created Date: Jun 19 2018 11:33AM