Using CMFs

Using the CMF Clearinghouse to find and identify a CMF is often only the first step for a transportation practitioner. The following resources provide practical guidance on using CMFs.

Quick Start Guide to Using CMFs
Are you new to using CMFs? This Quick Start Guide provides a 2-page overview of the process of selecting CMFs for prospective countermeasures and applying the CMFs to estimate safety benefits.

CMFs in Practice
The CMFs in Practice Series includes five separate guides that identify opportunities to consider and quantify safety in specific activities, including roadway safety management processes, road safety audits, design decisions and exceptions, development and analysis of alternatives and value engineering. The series also includes reference documents that provide background information on crash modification factors and safety performance functions.

Investigation of Existing and Alternative Methods for Combining Multiple CMFs
This paper brings to light several issues associated with the application of multiple CMFs and provide guidance on how to estimate the combined treatment effect when multiple treatments are installed at a given location. The paper presents several existing methods for combining multiple CMFs and discusses the associated issues. Next, several ideas are explored for overcoming the identified issues. Finally, the methods are applied and compared to existing CMFs for multiple treatments in an attempt to validate the new procedures.


  • Application of Crash Modification Factors Course (Self-Paced Lesson and Live Webinar)
    This course focuses on the application of Crash Modification Factors (CMFs) to select countermeasures. It covers the project development cycle (starting from network screening and site selection for safety review), diagnostics of safety concerns, cost-benefit evaluation, and countermeasure selection. Upon completion of the course, participants will be able to explain how CMFs are used to estimate the safety effects of highway improvements and apply CMFs to compare and select highway safety improvements. This course combines a web-conference and a self-paced lesson that aids in application to your current projects.