Establishing crash modification factors and their use.

PDFTech ReportFHWA-PA-2014-005-PSU WO 6LTI 2015-024400008014, PSU 006Highway safetyTraffic accidentsCountermeasuresImplementationTrainingPennsylvaniaMid-Atlantic Universities Transportation CenterGayah, Vikash V.Donnell, Eric T.Thomas D. Larson Pennsylvania Transportation InstituteUnited States. Federal Highway AdministrationPennsylvania. Dept. of Transportation. Bureau of Planning and ResearchUS Transportation CollectionA critical component in the Association of State Highway and Transportation Officials\ue2\u20ac\u2122 (AASHTO) Highway Safety Manual(HSM) safety management process is the Crash Modification Factor (CMF). It is used to estimate the change in theexpected (average) number of crashes at a site when a specific countermeasure is implemented. This project responds to arequest from the Pennsylvania Department of Transportation (PennDOT) to help integrate the use of CMFs into the existingsafety management process. The objectives of this project were to assemble a list of CMFs that are consistent with the HSMand are appropriate for use in Pennsylvania, and provide guidelines for their use. Two products were created to helpachieve these objectives. The first product is a guidebook that describes the proper implementation procedures for CMFsand contains a complete list of CMFs that are appropriate for use in Pennsylvania. This guidebook is the Pennsylvania CMFGuide. The second product is a training presentation for PennDOT entitled What are CMFs and how do you use them? Thispresentation will be used to introduce engineers to CMFs, describe how to implement them, and provide guidance for how touse the Pennsylvania CMF Guide. This presentation is geared toward both internal and external training workshops.The remainder of this report provides details on the development of these two products, which are included as appendices