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.