The National Academies

NCHRP 17-95 [Active]

Crash Modification Factors (CMFs) for Intelligent Transportation System (ITS) Applications

  Project Data
Funds: $400,000
Staff Responsibility: Edward T. Harrigan
Research Agency: University of North Carolina at Chapel Hill
Principal Investigator: Raghavan Srinivasan
Effective Date: 6/1/2020
Completion Date: 9/1/2022


It is generally understood that Intelligent Transportation System (ITS) applications, such as variable/dynamic/changeable message signs, closed-circuit television (CCTV) cameras, traffic monitoring stations, ramp meters, and Road Weather Information Systems (RWIS), help manage traffic and improve incident response, thus enhancing roadway safety. However, actual data, specifically crash reduction data resulting from ITS applications, are very limited. Research is needed to develop crash modification factors (CMFs) for the various, typically deployed ITS applications.

This research will inform engineers, transportation agencies, and the public of the safety benefits of ITS applications by quantifying the reduction in crash frequency and severity resulting from their deployment. Further, it will help justify and obtain safety-related funding for ITS applications, as well as provide quantifiable information to support the need for ITS applications to transportation project delivery teams, planning organizations, and the public.

This research is specifically relevant to the American Association of State Highway and Transportation Officials (AASHTO) Committee on Transportation System Operations (CTSO), Subcommittee on Technology, Working Group on Intelligent Transportation Systems; the AASHTO Committee on Safety; and the AASHTO Technical Committee on Roadside Safety.


The objective of this research is to address a long-standing deficiency in safety related ITS data by developing (1) CMFs for commonly deployed ITS applications, independently and as a part of systems and (2) case studies of safety benefit/cost ratio calculations for such ITS applications. The CMFs shall be suitable for use by safety professionals in their analyses and shall meet at least a CMF Clearinghouse four-star quality rating.

The research shall consider ITS applications deployed on freeways, arterials, and rural highways. ITS applications may include, but not be limited to, established devices and treatments such as variable/dynamic/changeable message signs, CCTV cameras, traffic monitoring stations, active warning signs, ramp meters, and RWIS.


Phase II is in progress. The Phase I interim report is available upon request to NCHRP.

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