M&M was selected by the client to replace the dual existing three-span, 750’ steel deck truss bridges as well as a three-span mainline bridge just north of the deck truss bridges. In the early 1950’s, the existing truss bridges were designed (by M&M) as a critical link on the new Northeast Extension (I-476) of the Pennsylvania Turnpike.
At 190’, the Hawk Falls Bridges are the highest bridge on the entire Pennsylvania Turnpike and are located within the pristine Hickory Run State Park. Following an extensive evaluation of the existing bridges, M&M recommended that the PTC replace the existing bridges since they are nearing the end of their service life and are functionally obsolete. The replacement bridge will be a single 720’ long steel bridge featuring a 480’ three-rib deck arch span flanked by steel plate girder approach spans. Similar to the existing configuration, the replacement bridge will carry two traffic lanes in each direction and will also provide 12-foot-wide outside shoulders and 6-foot-wide median shoulders. Welded, steel box arch ribs will be utilized to create an aesthetically pleasing structure that spans the deep Mud Run Valley. In addition to replacement of the deck truss bridges, the existing three-span bridge carrying the I-476 mainline over SR 534 will be replaced with a 120’ single span, steel plate girder bridge.
Construction is started in 2023 and is ongoing.
|Length of Main Span
|Total Project Length
|Lanes on Structure
|4 Travel Lanes (with future widening possible)