Validation and Application of Highway Safety Manual (Part D) and Developing Florida CMF Manual, Phase 2

The Highway Safety Manual (HSM) Part D provides a comprehensive list of the effects of safety treatments (countermeasures). These effects are quantified by crash modification factors (CMFs) which are based on compilation from past studies of the effects of various safety treatments. The HSM Part D provides CMFs for treatments applied to roadway segments, intersections, interchanges, freeways, and special facilities. Nevertheless, it is essential to verify the applicability of the HSM CMFs in specific locales. The objectives of this study are (1) to develop CMFs for various treatments in Florida for the same setting (rural/urban), road types, crash types, and severity levels, (2) to evaluate the difference between these Florida-specific CMFs and the CMFs in the HSM, and (3) to recommend whether the CMFs in the HSM can be applied to Florida or new Florida-specific CMFs are needed. Moreover, in phase II, various Florida-specific CMFs and crash modification functions (CMFunctions) were estimated for the most common treatments in Florida. As with phase I of the project, there is a need to improve some CMFs that had insufficient data. An alternative way to combine multiple CMFs to identify the effectiveness of multiple treatments was suggested in this study. Different methods of observational studies were used to calculate CMFs and to develop CMFunctions for a total of 37 additional treatments applied to roadway segments, intersections and special facilities. It was found that Florida-specific CMFs were generally statistically significant, and the safety effects represented by the CMFs were intuitive, similar to the CMFs in the HSM. It was also found that Florida-specific CMFs for the treatments not included in the HSM showed significant positive effects in reducing crash frequencies. The authors also present a Florida-specific manual of CMFs.


  • English

Media Info

  • Media Type: Digital/other
  • Edition: Final Report
  • Features: Appendices; Figures; References; Tables;
  • Pagination: 343p

Subject/Index Terms

Filing Info

  • Accession Number: 01602593
  • Record Type: Publication
  • Contract Numbers: BDV24‐977‐05
  • Created Date: Jun 23 2016 4:02PM