The Wisconsin Department of Transportation (WisDOT) was looking to evaluate the traffic safety and operations of the Southeast Wisconsin freeway system using the Interactive Highway Safety Design Model (IHSDM) and Vissim. raSmith was one of two firms retained by WisDOT to conduct an IHSDM evaluation on nearly every freeway corridor and system interchange in Southeast Wisconsin. Traffic operations in several corridors were analyzed using Vissim microsimulation traffic flow modeling software. The safety and operational results were then used as the basis of a benefit-cost analysis for corridors with design alternatives.
Wisconsin had not used IHSDM to evaluate safety performance in this magnitude prior to this project. This was a distinctive effort, one with the capacity to assist WisDOT with selecting appropriate and cost-effective scopes of work for future improvement projects.
The combined project team used the IHSDM Crash Prediction Module (CPM) to evaluate the 300 miles of freeway in the Southeast Region. A significant amount of data was used for the evaluation. The various data sources that were utilized included roadway alignment, traffic volumes, crashes, geometric data, Meta Manager data, and roadside barrier information.