The new I-76 Allegheny River Bridge is the first cast-in-place concrete segmental bridge in Pennsylvania and features a 532’ long main span across the Allegheny River. The twin 2,350’ long structures were built on an alignment parallel to the existing turnpike. Additionally, the bridge spans Freeport Road, active rail lines, the side channel of the river used by recreational boaters and Fourteen Mile Island, part of the Allegheny Island State Park.

The bridge accommodates six lanes of traffic, plus acceleration and deceleration lanes for the Allegheny Valley Interchange at the western end of the bridge. The project includes bridge approaches, reconstruction of the toll plaza and associated ramps and three smaller bridges over the Turnpike.

Aesthetic features were developed in a design charette, drawing inspiration from the site’s natural landscape. The design includes a variable-depth superstructure and rectangular piers adorned with a stone pattern, featuring concave curves in the transverse direction. Both the superstructure and substructure showcase harmonious parabolic curves, seamlessly integrating the two elements into an elegant and cohesive form.

Construction occurred between the 2007 USGA Open and the 2010 LPGA Open, both held at the historic Oakmont Country Club which is located adjacent to the bridge site. Balanced cantilever construction allowed uninterrupted access for Turnpike, highway, rail, and river traffic throughout the duration of construction. GM2’s Complex Bridge team was on-site throughout construction providing construction engineering and inspection services.