CMF Clearinghouse


CMF Clearinghouse Update: Summer 2023

In this issue:

  • Did you miss the CMF Clearinghouse Annual Webinar?
  • Upcoming Change: New Domain and Website Improvements
  • Upcoming Change: Comments on Older Studies That Did Not Explicitly Report CMFs
  • Featured CMFs
  • Submit a Study

The Summer 2023 edition of CMF Update is the 27th edition of the CMF Clearinghouse e-newsletter. To subscribe, please visit To view archived issues, please visit To view the CMF Clearinghouse brochure, please visit

Did you miss the CMF Clearinghouse Annual Webinar?

Click HERE to watch the recorded webinar on Practicing What We...Research: How to Apply CMFs in Road Safety Audits, Consider CAVs/Technology, and Understand Recent Federal Research, download the presentations, or review the webinar questions and answers.

During the December 2022 webinar, Matt Hinshaw, Federal Highway Administration (FHWA), provided an overview of the CMF Clearinghouse. Kate Bradbury, Parametrix, presented on the use of CMFs in a Road Safety Audit (RSA) for Olympic National Park. Karen Timpone, FHWA, and Raul Avelar, Texas A&M Transportation Institute (TTI), presented on the impacts of CAV technology on proven safety countermeasures. Taha Saleem, with the University of North Carolina Highway Safety Research Center (HSRC) and manager of the CMF Clearinghouse, provided an overview of the various current and recently completed CMF-related National Cooperative Highway Research Program (NCHRP) projects.

Do you ever feel like there's so much information on the Clearinghouse website that you have trouble finding exactly what you need? Taha Saleem, HSRC, presented an overview of available resources and demonstrated how to make use of the CMF Clearinghouse features, including how to sort through hundreds of countermeasures and CMFs to find the most appropriate CMF for your situation.

Upcoming Change: New Domain and Website Improvements

The end of the URL for the CMF Clearinghouse website will be changing from .org to This change is expected to have no impact on CMF Clearinghouse users (and redirects will be set up to help you get to where you need to be from old links).

The CMF Clearinghouse team has also been working hard behind the scenes making numerous updates and upgrades on the backend of the site (including changing from ColdFusion to PHP programming language) to improve the experience and usability for all of its users.

More information about these changes will be forthcoming, but no impact – only improved service – is expected for CMF Clearinghouse users.

If you have specific questions regarding the PHP re-programming or the domain change, contact Matt Hinshaw ( or Taha Saleem (

Upcoming Change: Comments on Older Studies That Did Not Explicitly Report CMFs

One of the criteria for a CMF to be included in the CMF Clearinghouse is for studies to explicitly present quantified CMF values or CMFunctions. The CMF Clearinghouse presents the CMFs as they are presented by the author in the original source document (i.e., the Clearinghouse team does not derive CMFs if they are not explicitly reported by the author). There is no modification made to the CMF value or adjustment to any reported standard error.

Did you know that in the early years of CMF Clearinghouse some CMFs that were not explicitly mentioned in the studies and derived by the CMF Clearinghouse reviewers were included in the CMF Clearinghouse?

The CMF Clearinghouse team has been revisiting studies to identify CMFs that were not explicitly reported by the authors at the time of submission. Once this review is complete, we will be adding comments to the CMFs in question identifying that they were derived based on the data presented in the study and were not explicitly mentioned by the authors. We will also be updating the FAQ section to clarify what these comments mean.

Featured CMFs 

Crash Modification Factor (CMF) Value: 0.84 (for run-off-road and sideswipe on 4-lane roadways)

Star Quality Rating: 2 Stars


Crash Modification Factor (CMF) Value: 0.498 (for all vehicle-bicycle crashes)

Star Quality Rating: 4 Stars

Submit a Study 

The CMF Clearinghouse welcomes CMF study submissions to be included in its searchable database. If you wish to submit your CMF study, please email Matt Hinshaw at Be sure to search the Clearinghouse before submitting a new CMF as we may already have it listed. You may either send a link to a resource already existing on the web (preferred) or include it as an attachment in the email. Submissions might include published research studies that are not presented in the Clearinghouse, or state-specific CMFs that were developed as part of the Highway Safety Improvement Program. Please note that the Clearinghouse only includes CMFs that are derived and presented in the studies by the authors.

Funded by the U.S. Department of Transportation
Federal Highway Administration and maintained by the
University of North Carolina Highway Safety Research Center.

For more information, contact Matthew Hinshaw, FHWA Office of Safety, 360-753-9481.