NCHRP Implementation Support Program. Implementing the Areawide Approach to Roadway Safety Management and Safety Planning

Quantitative safety analysis is a relatively new field, and crash prediction modeling and other data-driven safety analysis procedures traditionally focus on the project level within state departments of transportation (DOTs). Many decisions affect safety or constrain safety improvement options later in a project’s lifecycle, and these decisions could benefit from quantitative safety analysis. Macro-level crash prediction models (CPMs) are a quantitative safety analysis method that predict an average crash frequency, by crash type and severity, for a defined area, such as a census block group, tract, traffic analysis zone, or county. NCHRP Research Report 1044: Development and Application of Quantitative Macro-Level Safety Prediction Models describes macro-level CPMs designed for a quantitative consideration of safety in planning-level decisions. This supports a proactive and comprehensive approach to addressing safety needs for all road users. Macro-level CPMs were developed for inclusion in the AASHTO Highway Safety Manual, second edition, in a chapter titled, “Areawide Approach to Roadway Safety Management.” The development process involved utilizing state- and metropolitan planning organization (MPO)-level data from three MPOs (Richmond, VA; St. Louis, MO; and Chicago, IL) and two states (Illinois and Utah). NCHRP Research Report 1044 observed a high level of consistency between the individual agency models, as well as the ability to integrate data and models into a combined model that incorporated more than one agency. Supplementing NCHRP Research Report 1044 are (a) a spreadsheet tool to support the testing and implementation of the macro-level CPMs; and (b) NCHRP Web-Only Document 348: Macro-Level Analysis of Safety Planning and Crash Prediction Models: A Guide, which provides guidance on how to use the spreadsheet tool. There is a need to provide technical guidance and training to state DOTs to implement the CPMs from NCHRP Research Report 1044 to address safety needs across diverse scenarios. The objectives of this research are to (a) provide technical help to state DOTs to implement the macro-level CPMs from NCHRP Research Report 1044, (b) conduct pilot projects with state DOTs, and (c) develop supplemental materials for the macro-level CPMs based on the results of the pilot projects.


  • English


  • Status: Proposed
  • Funding: $250000
  • Contract Numbers:

    Project 20-44(53)

  • 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:

    Zelinski, Patrick

  • Start Date: 20240214
  • Expected Completion Date: 0
  • Actual Completion Date: 0

Subject/Index Terms

Filing Info

  • Accession Number: 01887818
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 20-44(53)
  • Files: TRB, RIP
  • Created Date: Jul 17 2023 11:37PM