Interstate 378 Pennsylvania
Interstate 378 was the original designation for the freeway connecting U.S. 22 (Lehigh Valley Thruway) near Lehigh Valley International Airport (ABE) with Downtown Bethlehem. Designated Pennsylvania State Route 378, the short spur winds southeast from the Westgate and Notre Dame Hills neighborhoods to the Hill to Hill Bridge spanning the Lehigh River. Interchanges along the route are numbered sequentially and increase from north to south.
The Bethlehem freeway spur was constructed between 1966 and 1968.1 The route was signed as I-378 until the proposed realignment of Interstate 78 south of Allentown and Bethlehem was finalized. The American Association of State Highway Officials (AASHO) approved the elimination of Interstate 378 and the adjacent Allentown Spur (I-178), on June 30, 1970. I-78 was subsequently dropped from the Lehigh Valley Thruway, which remains as U.S. 22. The former I-378 was renumbered as part of Pennsylvania Route 378, a 9.55 mile long route stretching south to PA 309 in Upper Saucon Township.
Interstate 378 was also previously proposed to extend south across the Lehigh River to an interchange with a separate planned freeway: Constitution Drive to the west and South Side Spur to the east. The South Side Spur was projected to go east and south to the realignment of I-78.
Pennsylvania 378 Annual Average Daily Traffic (AADT)
|Location||Vehicles per day|
|Main St to Union Bl||28,000|
|Exits 3 to 2||28,000|
|Exits 2 to 1||28,000|
|Exit 1 to US 22||28,000|
North End / Lehigh Valley Thruway – Bethlehem, Pennsylvania
The eastbound on-ramp from the end of PA 378 joins a collector distributor roadway to adjacent Schoenersville Road. U.S. 22 (Lehigh Valley Thruway) runs between Allentown and Lehigh Valley International Airport (ABE) west to I-476 (PA Turnpike) at South Whitehall Township and I-78 at Upper Macungie Township. 09/01/05
South End / Hill to Hill Bridge – Downtown Bethlehem, Pennsylvania
South at Hill to Hill Bridge
North at Hill to Hill Bridge
Page updated June 10, 2022.