Development of Roundabout Crash Prediction Models and Methods

The objective of this research is to develop safety performance functions (SPFs) and crash modification factors (CMFs) for all road users (including non-motorized users) that can be used to estimate the severity and number of crashes likely to occur at roundabouts (a roundabout is defined in NCHRP Report 672: Roundabouts: An Informational Guide – Second Edition), under a variety of rural and urban contexts for single-lane and multilane roundabouts. The results of this research should enable transportation agencies to quantify the safety effects of roundabout design features and the safety performance of implementing a roundabout at a particular location so that safety performance can be compared to alternative intersection configurations for the same location. The research should answer the following questions at a minimum: (1) How do geometric features—and combinations of features—influence the number and severity of crashes at the roundabout? (2) How do operational features—and combinations of features—influence the number and severity of crashes at the roundabout? (3) How do driver learning curves influence the number and severity of crashes at any age roundabout? The results of this research should be presented in such a way that they can easily be incorporated into (1) a future edition of the Highway Safety Manual (HSM); (2) the AASHTO SafetyAnalyst software; and (3) the Interactive Highway Safety Design Model software.


  • English


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

    Project 17-70

  • 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:

    Hartell, Ann

  • Performing Organizations:

    Kittelson and Associates

    1818 Library Street, Suite 500
    Reston, VA  United States  20190
  • Principal Investigators:

    Ferguson, Erin

  • Start Date: 20140714
  • Expected Completion Date: 20180228
  • Actual Completion Date: 20180228
  • Source Data: RiP Project 37698

Subject/Index Terms

Filing Info

  • Accession Number: 01545247
  • Record Type: Research project
  • Source Agency: Transportation Research Board
  • Contract Numbers: Project 17-70
  • Files: TRB, RiP
  • Created Date: Nov 26 2014 1:00AM