The US 30 Reconstruction Program includes a 14.5-mile freeway section with eight interchanges that passes through the City of Coatesville, Downingtown Borough, and Caln, East Caln, Sadsbury, Valley, West Brandywine, West Caln, and West Sadsbury Townships in Chester County, Pennsylvania. The facility was constructed in the late 1950s and early 1960s, providing an important link in the regional transportation network. Through a series of projects, PennDOT will upgrade the facility to improve safety, reduce congestion, accommodate planned growth, improve facility deficiencies, and improve system connectivity.

 

McMahon is a major subconsultant on the PennDOT project, providing traffic data collection, traffic operations analyses, visual microsimulation, public involvement, and safety analyses. The project is currently in the conceptual design phase, evaluating alternatives along the corridor, gathering feedback and input from stakeholders and the public at the county, municipal and local levels.  

 

The Interactive Highway Safety Design Module (IHSDM) is a software analysis tool to evaluate the safety and operational effects of geometric design decisions on highways. IHSDM is a decision-support tool that provides estimates of a highway design’s expected safety and operational performance to support decision making in the highway design process. As part of our role on this contract, McMahon is utilizing the Crash Prediction Module within IHSDM, which incorporates the most current analytical methods by directly implementing Part C of the Highway Safety Manual to:

 

• Predict crash frequency for highway segments, intersections and interchanges;

• Evaluate the safety effects of highway improvements and treatments;

• Compare relative safety performance of design alternatives; and

• Asses the safety of design decisions. 

 

The results of the IHSDM Crash Prediction Module are a factor in the evaluation of multiple design alternatives.