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DCMF Studies

The Federal Highway Administration (FHWA) Development of Crash Modification Factors (DCMF) program was established in 2012 to address highway safety research needs for evaluating new and innovative safety strategies (improvements) by developing reliable quantitative estimates of their effectiveness in reducing crashes.


1. Enhancing Statistical Methodologies for Highway Safety Research – Impetus from FHWA, Publication Number FHWA-HRT-14-081

A goal of the DCMF program is to advance highway safety and related research by establishing a sound foundation for the development of statistical methodologies that need to be specifically developed for highway transportation applications in cooperation with the American Statistical Association (ASA) and other statistician communities. In pursuit of that goal, a 2-day Technical Experts meeting brought together researchers from the road safety and statistics fields and other fields related to statistics—such as epidemiology, biostatistics, and agent-based modeling—that have methodologies relevant to highway safety research applications. The meeting resulted in guidance and materials that supported the development of the publication, which identifies and discusses opportunities for advancing methodologies to estimate crash modification factors and safety performance functions. The publication outlines considerations and future steps to encourage researchers to explore these techniques in their research.

2. Crash Modification Factors Needs Assessment Workshop Summary Report, Publication Number FHWA-HRT-15-020

On May 28, 2014, FHWA hosted a Crash Modification Factor (CMF) Stakeholder Meeting to provide a forum for CMF stakeholders to communicate ongoing efforts and identify opportunities for future collaboration. CMF stakeholders represent two primary groups: the CMF user community (transportation agencies and practitioners) and the CMF research and development community (individuals and agencies who plan, fund, direct, and carry out CMF research). Bringing these stakeholders together provided an opportunity to share insights and resources to further advance the research and development of CMFs and related activities.

The CMF Needs Assessment study was completed in June 2014, and its products below were used to enhance FHWA, CMF Clearinghouse, and related CMF studies.

3. Contributing Factors for Focus Crash and Facility Types, HRT-20-052

4. Contributing Factors for Focus Crash and Facility Types: Quick Reference Guide, HRT-20-053

The Focus Crash Types and Risk Factors (FCT-RF) study is a data-driven study to use scientific and reliable expertise, data resources, methodologies and procedures, and tools and required resources to determine sets of highway focus crash types and focus facilities and their associated risk factors for safety prioritization and systemic improvement applications.

The FCT-RF will identify appropriate low-cost safety strategies for possible systemic safety improvements implementation on the focus facilities.

The product of this study will be used for upcoming FHWA-related highway safety research and published and shared with the Transportation Research Board (TRB), American Association of State Highway and Transportation Officials (AASHTO), National Highway Traffic Safety Administration (NHTSA), American Statistical Association (ASA), University Transportation Centers (UTC), and other government agencies and highway safety stakeholders.

5. The Development of Crash Modification Factors: Highway Safety Statistical Paper Synthesis, HRT-20-069

The objectives of this project are to:

  • Review and critically synthesize recent papers that explore refinements to current research methods (including study design and statistical analysis), or propose new methods to assess the safety performance of highways and streets. This may include, but is not limited to, estimating safety performance functions (SPFs) and developing CMFs. The critical synthesis will be a resource to researchers and others looking to advance the science of highway safety.
  • Disseminate the findings of the project to highway safety stakeholders. This dissemination will include the identification of those areas with the greatest potential for future efforts to advance the science of highway safety performance, and workshops for various traffic safety stakeholders.

6.The DCMF Expert Statistician Support Team (August 2016-2019)

The objective of this Task Order is to work with an Expert Statistician Support Team (ESST) to complete the following tasks:

  • Review the Focus Crash Types and Risk Factors study deliverables and provide technical feedback. 
  • Review and provide technical feedback for the Statistical Papers Synthesis study. 
  • Work with FHWA and the ELCSI-PFS study team to identify reliable and effective methodologies for up to eight new safety evaluations for:
    • designing a work plan.
    • variable selection.
    • sample collection.
    • data analysis.
  • Review of interim and final products.

7. The Wrong Way Driving Low-Cost Safety Improvements (Completion date: 08/2022)

This study identified and evaluated subset of WWD countermeasures that are most commonly used in the United States, and developed CMFs and Benefit-to-Cost ratios. The NCRHP Report 881 revealed that there is no one traffic control device that can reduce wrong-way movements across all different roadway types (high-speed rural divided highways, high-speed urban divided highways, freeways, etc.). The NCHRP study identified traffic control devices that may be effective in reducing wrong-way movements on high-speed divided highways and freeways, and were included in this evaluation for: DO NOT ENTER and WRONG WAY signs using a larger sign on the outside of a wrong-way turn; Wrong-way arrow markings for the through lanes on the divided highway; Pavement markings for turning lane paths; and Use of stop lines when interior right-of-way treatments are provided.

This study held a workshop for Federal, State, and local agencies that are interested in WWD safety improvements.