CMF Clearinghouse


CMF Clearinghouse Update: Summer 2021

In this issue:

  • CMF Clearinghouse Rating System Transition
  • Resource: Countermeasure Service Life Guide
  • Resource: Selecting Projects and Strategies to Maximize HSIP Performance
  • Featured CMFs
  • Submit a Study

The summer 2021 edition of CMF Update is the 23rd edition of the CMF Clearinghouse e-newsletter. To subscribe, please visit To view archived issues, please visit


CMF Clearinghouse Rating System Transition

The CMF Clearinghouse transitioned to the CMF rating criteria developed as part of the NCHRP 17-72 project for the Update of CMFs for the Highway Safety Manual on February 15, 2021. This new rating system is more rigorous than the legacy CMF Clearinghouse rating criteria and provides scores for different factors including sample size, study design, methodology, and statistical significance.

The CMF Clearinghouse continues to present CMF rating on a 5-Star scale, along with the total score calculated using the NCHRP 17-72 rating criteria. Legacy Ratings for all the CMFs (prior to the rating system transition) have been converted to reflect the new rating criteria. The transition to the NCHRP 17-72 rating criteria has led to few instances where the star ratings for current CMFs have changed (there are some higher rated CMFs that score lower under the new rating criteria, as well as some lower rated CMFs that score higher under the new rating criteria). To minimize the impact of these changes, this SPREADSHEET  is available to the CMF Clearinghouse users to compare the legacy star ratings vs. the new star ratings for all the current CMFs (prior to the rating system transition). CMFs added to the CMF Clearinghouse after the rating system transition will only be rated using the new criteria.

There are several resources available on the CMF Clearinghouse that provide additional information about the rating transition:

  • This FLYER provides an overview of the legacy CMF Clearinghouse star rating criteria, as well as the NCHRP 17-72 criteria. This FLYER provides details about what has changed as a result of this rating transition and how these changes might impact users.

  • The archived Practitioner and Researcher focused webinar recordings describe the rating system changes, how to navigate these changes on the CMF Clearinghouse website, where to find the legacy ratings, details of the new rating criteria, how to ensure your upcoming research work produces highly rated CMFs, tools available on the CMF Clearinghouse website to provide guidance on the use of CMFs, and what you can do to minimize the impacts of this transition to your work. Further information on these webinars including the presentation slides and Q&As can be found on the CMF Clearinghouse website.

  • The CMF Clearinghouse User GuideFrequently Asked Questions (FAQs)Star Quality Rating page, and the Relationship to the Highway Safety Manual page were also recently updated to reflect the CMF Clearinghouse rating system transition.

If you have specific questions regarding this rating system transition, contact Karen Scurry ( or Taha Saleem (


Resource: Countermeasure Service Life Guide

Countermeasure Service Life Guide provides transportation practitioners with the necessary information to make consistent, data-driven decisions for evaluating and prioritizing safety countermeasures using prescribed countermeasure service lives. This Guide provides typical service lives for a wide range of safety countermeasures and demonstrates the benefits to standardizing countermeasure service life application throughout an agency. It also provides background information on factors that can impact countermeasure service life and analytical considerations when conducting benefit-cost analysis for multiple countermeasures or alternatives with differing service life.


Resource: Selecting Projects and Strategies to Maximize HSIP Performance

The Selecting Projects and Strategies to Maximize Highway Safety Improvement Program (HSIP) Performance Guide presents fundamental analytical methods and a conceptual framework for maximizing the effectiveness of the HSIP by increasing the individual performance of its projects. The best performing, most-cost-effective, highest-priority HSIP projects deliver the greatest reductions in fatalities and serious injuries at the lowest costs. To address fatal and serious-injury crashes, agencies should focus on the change in fatal and serious-injury crashes, rather than all crashes or all injuries, when selecting projects.

Agencies can use these findings and the HSIP to potentially help save more lives and prevent more serious injuries. While more complete and higher-quality data can help identify locations and projects with the greatest potential to improve safety, States can implement the concepts and methods of benefit-cost ratio prioritization with almost any level of data. Researchers can assist practitioners by developing new tools that apply these methods, as well as expanding the library of available SPFs and CMFs by severity level and implemented countermeasure data.


Featured CMFs 

Crash Modification Factor (CMF) Value: 0.684 (for winter – October to March – crashes on rural highways)

Star Quality Rating: 4 Stars


Crash Modification Factor (CMF) Value: 0.858 (for all crashes)

Star Quality Rating: 4 Stars


Crash Modification Factor (CMF) Value: 0.633 (for all crashes)

Star Quality Rating: 5 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 Karen Scurry 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.

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 Karen Scurry, FHWA Office of Safety Programs 609-637-4207