Enhancing Freeway Safety Prediction Models

Safety prediction models have been developed for urban freeway segments in Texas and elsewhere to apply to cross sections up to 10 lanes wide. These models are documented resources such as TxDOT’s Roadway Safety Design Workbook and the Highway Safety Manual (HSM), and applied in several spreadsheet-based analysis tools. These tools are acknowledged in the Project Development Process Manual and have been used by various district personnel, particularly in the evaluation of project alternatives or analysis of design exceptions. However, additional research is needed to address knowledge gaps as well as to develop updated local calibration factors for the models. Specifically, safety prediction models do not exist for 12-lane freeway segments or freeway segments with managed lanes (such as high-occupancy-vehicle or high-occupancy-toll lanes). This research project will develop new safety prediction models for 12-lane freeway segments and segments with managed lanes, and also derive local calibration factors for models for urban freeway segments with 4-10 lanes. The project will also develop an analysis tool to help practitioners implement the new models to facilitate analysis of complex urban freeway configurations, such as cases where an urban freeway widening project requires challenging tradeoffs between narrowing lanes or inside or outside shoulders.


  • English


  • Status: Completed
  • Funding: $275000
  • Contract Numbers:


  • Sponsor Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483

    Federal Highway Administration

    1200 New Jersey Avenue, SE
    Washington, DC  United States  20590
  • Managing Organizations:

    Texas Department of Transportation

    125 E. 11th Street
    Austin, TX  United States  78701-2483
  • Project Managers:

    Pridgen, Shelley

  • Performing Organizations:

    Texas Transportation Institute

    Texas A&M University System
    3135 TAMU
    College Station, TX  United States  77843-3135
  • Principal Investigators:

    Pratt, Michael

  • Start Date: 20200101
  • Expected Completion Date: 20220630
  • Actual Completion Date: 20220630

Subject/Index Terms

Filing Info

  • Accession Number: 01744091
  • Record Type: Research project
  • Source Agency: Texas Department of Transportation
  • Contract Numbers: 0-7067
  • Files: RIP, STATEDOT
  • Created Date: Jun 25 2020 2:54PM