A68/NB-391 Bridge Replacement

The Pennsylvania Turnpike Commission has retained Erdman Anthony for design management, construction project management, and inspection services for the design/build NB-391 Bridge replacement project located at milepost A68.53 on the Pennsylvania Turnpike System in Lehigh County, PA.
The project includes the replacement of the NB-391 Bridge carrying turnpike traffic over SR 4018 (Main Street) and Trout Run on the Northeast Extension in Washington Township, Lehigh County. The existing three-span steel-girder/floor-beam structure is being replaced with two three-span steel-plate girder bridges. Both bridges have a length of 533 feet and a vertical clearance of 87 feet and nine inches. The new structures are supported by stub abutments on micropiles and piers on eight-foot diameter concrete caissons bearing on bedrock. Random stone slope walls were constructed in front of the abutments to help prevent future erosion.
Roadway improvements include partial milling and full-depth reconstruction, widening to the ultimate six-lane width, significant earthwork, and a steel-pile retaining wall. The project also includes the installation of water-quality best management practices (rain gardens, vegetated swales, and subsurface infiltration beds).
During stage 1, traffic was maintained on the existing bridge/alignment, and most of the earthwork and the outside half of the structures were completed. The four lanes of traffic were then moved to the new outside structures. The inside half of the structures and roadway are now under construction.  

Project Details


Lehigh County, PA


Pennsylvania Turnpike Commission



Construction Cost

$34.5 Million

Project Contact

Noel Caron, PE
  • Noel Caron, PE
  • 717-766-1741 x 5009
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