McMahon was retained to provide transportation engineering services for this interchange Improvement project by PennDOT District 5-0. McMahon had previously completed a Transportation Impact Fee Roadway Sufficiency Analysis and Capital Improvement Plan for Bethel Township which included the interchange. Based on this background traffic study and a Traffic Impact Study prepared for the adjacent Berks County Industrial Development Authority, McMahon developed multiple design alternatives for PennDOT to evaluate.

 

The final design selected for this project was a complete bridge replacement which will allow for future widening of I‐78 from a 4 lane divided highway to a 6 lane divided highway. S.R. 0501 was widened to 4 lanes from 2 lanes and traffic signals were installed at both ramp intersections.  McMahon developed a traffic control plan that constructed the bridge in two sections to limit closures and maintain access for truck traffic for all except five days of construction. The new bridge consists of a single span pre-stressed concrete PA-bulb-tee beam structure.

 

Construction was approximately $10 million. Project tasks included topographic survey, conceptual design plans, alternatives analysis, public involvement, bridge design, signal design, and roadway design.