Calibrating Crash Modification Factors for Wyoming-Specific Conditions: Application of the Highway Safety Manual - Part D

The Highway Safety Manual (HSM) provides a quantitative measure of safety of various countermeasures known as Crash Modification Factors (CMF). CMFs provided in the HSM are calibrated based on data collected from a few states with specific roadway and climate characteristics in the US, which may not represent the same safety efficacy of countermeasures implemented in other regions. In this regard, Phase 1 of this project was aimed towards validating the applicability of the HSM to Wyoming conditions. Phase 2 of this project was carried out to fulfil the same objectives with conducting analysis to other countermeasures. The countermeasures which were analyzed in this study included 1) combined shoulder and centerline rumble strips, 2) centerline rumble strips only, 3) adding lane and divide, 4) snow fences, 5) variable speed limit corridors, 6) non-conventional intersections/interchanges (roundabout and diverging diamond interchange), and 7) urban/suburban five lane arterial corridors. Massive data collection efforts have been made to develop crash modification factors. This study provided a set of methodologies to collect and impute data required for the application of the HSM. Moreover, the study verified and confirmed the suitability of other statistical techniques to assess the safety efficacy of countermeasures where data needed are not available. The results indicated that the majority of these countermeasures are statistically significant in reducing crash frequencies and/or severity.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; Maps; Photos; References; Tables;
  • Pagination: 141p

Subject/Index Terms

Filing Info

  • Accession Number: 01765583
  • Record Type: Publication
  • Report/Paper Numbers: WY-17/04F Vol 2
  • Contract Numbers: RS09217
  • Created Date: Jan 29 2021 1:54PM