Register for the free webinar!

The Right Fit: Finding and Applying the Right CMF for the Job
Tuesday, December 12, 2:00-3:30pm Eastern Time

Learn about New Jersey's current practice for using safety performance functions and crash modification factors. Sophia Azam and her colleagues at New Jersey DOT will discuss how they use these tools for Highway Safety Improvement Program project selections and enhancements, and how they handle situations when site conditions do not perfectly match the prediction models.

Do you ever feel like there's so much information on the Clearinghouse that you have trouble finding exactly what you need? Daniel Carter will discuss how to select a CMF and will demonstrate how to make use of the features of the CMF Clearinghouse to sort through hundreds of countermeasures and CMFs to find the most appropriate CMF for your situation.

Conversion to KABCO severity scale

The CMF Clearinghouse is now using the KABCO scale to report the severity level of the crashes addressed by each CMF. From the launch of the Clearinghouse in 2009 until this recent change, the Clearinghouse had used a more generalized scale with values of Fatal, Serious Injury, Minor Injury, and Property Damage Only. However, the newest edition of the Model Minimum Uniform Crash Criteria Guideline implemented the terms "serious" and "minor" in severity definitions, causing an unintended parallel to the Clearinghouse severity scale. In order to avoid confusion and to better serve the majority of Clearinghouse users who use KABCO severity levels in their safety analysis, the Clearinghouse team revised all past CMFs with the equivalent KABCO severity. Moving forward, the Clearinghouse will use only KABCO severity for all CMFs.

Featured CMFs

Below are some CMFs that were added recently.

Convert a T intersection into a continuous green T intersection
Crash Modification Factor (CMF) Value: 0.958
(for all crashes)
Star Quality Rating:

Installation of safety edge treatment
Crash Modification Factor (CMF) Value: 0.87
(for all non-intersection crashes)
Star Quality Rating:

Install J-Turn intersection
Crash Modification Factor (CMF) Value: 0.877
(for all crashes)
Star Quality Rating:

Featured Resource

CMF Clearinghouse User Guide

New to the CMF Clearinghouse? Need help conducting searches on the Clearinghouse? The CMF Clearinghouse User Guide includes information about crash modification factor basics for those unfamiliar with CMFs and guidance on how to conduct searches. It also provides advanced tips on functionality for more experienced users. The User Guide is organized into the following sections:

Introduction to Crash Modification Factors: This section provides basic information about what CMFs are and how they are used.
Introduction to the CMF Clearinghouse: This section informs readers about the purpose and contents of the CMF Clearinghouse.
Searching for CMFs on the CMF Clearinghouse: This section shows users how to use the search functionality of the Clearinghouse to find CMFs.
Identifying Appropriate CMFs: This section provides guidance on interpreting search results and selecting the most appropriate CMF for a given situation.
Information for Advanced Users: This section provides information about CMFs and the Clearinghouse for those with more experience. It includes guidance on downloading extracts of the CMF Clearinghouse database and guidance on developing CMFs.

Tutorial videos are provided to accompany the user guide. They demonstrate how to use features of the Clearinghouse, such as how to conduct a search and how to filter a search result.

To view the guide, click HERE.

Featured FAQ

Who uses CMFs and how are they used?

CMFs are used by several groups of transportation professionals for various reasons. The primary user groups include highway safety engineers, traffic engineers, highway designers, transportation planners, transportation researchers, and managers and administrators. CMFs can be used to:

capture the greatest safety gain with limited funds;
compare safety consequences among various alternatives and locations;
identify cost-effective strategies and locations;
check reasonableness of evaluations (i.e., compare new analyses with existing CMFs); and
check validity of assumptions in cost-benefit analyses.

A few examples include:

A traffic engineer could use CMFs to evaluate the relative cost-effectiveness of several countermeasures for enhancing signal visibility. Countermeasures included increasing lens size, installing signal backplates, and installing dual red indicators in each signal head.
A highway designer could use CMFs to compare the cost and safety consequences between paved and unpaved shoulders.

A transportation planner could use CMFs to compare the long-term safety impacts of a series of roundabouts as opposed to a series of signalized and unsignalized intersections.

For more on this question, visit http://www.cmfclearinghouse.org/faqs.cfm.

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 karen.scurry@dot.gov. 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 upload your own file. 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.