I-78 Bridge Underclearance

Pennsylvania Department of Transportation | Berks County, PA

PennDOT’s Interstate 78 Bridge Underclearance Project replaced six overhead bridges located consecutively along an eight-mile stretch of Interstate 78 in western Berks County, Pennsylvania, utilizing accelerated bridge construction (ABC) techniques. Benesch was responsible for the design of three of the six replacement bridges on the project. The bridges were replaced to increase the minimum vertical clearance over Interstate 78 from approximately 14 feet to 16 feet 6 inches and to accommodate future Interstate 78 widening. The approach roadways and ramps were reconstructed as part of the project to accommodate roadway profile and width modifications.

All six replacement bridges are single-span prestressed concrete beam bridges that incorporate aesthetic features such as an architectural finish and color scheme. The substructure units typically consist of tall cantilever abutments supported on spread footings (one structure was supported on pile foundations).

The use of ABC techniques under roadway closures reduced the average construction duration for each structure from a year to 45 calendar days. ABC techniques utilized on the project included prefabricated bridge elements and time-based bidding techniques. Prefabricated bridge elements included precast concrete footings, stems, pedestals, back walls, deck panels, approach slabs, sleeper slabs, and moment slabs.


Practice Areas


  • 2018, Project of the Year, American Society of Highway Engineers - East Pennsylvania