Interstate 78 runs 144 miles from near Harrisburg, Pennsylvania to the Holland Tunnel approach in Jersey City, New Jersey, and is a primary New York City truck approach from the west. The route is heavily used by long-haul freight bypassing the I-95 / NJ Turnpike chokepoints.
For freight, I-78 is the preferred westbound exit from the New York metro for traffic bound for the Pennsylvania Turnpike or the Allegheny corridor. The Lehigh Valley segment near Allentown / Bethlehem is a major distribution hub. Amazon, FedEx, UPS, and major LTL carriers all operate facilities along I-78. Truck volumes are extreme. Freight moving through the Lehigh Valley is projected to grow about 96 percent to roughly 80 million tons a year by 2040 (Lehigh Valley Planning Commission), so daytime truck traffic on this stretch keeps climbing.
Geographically I-78 climbs the Blue Mountain ridge in eastern Pennsylvania, crosses the Lehigh Valley, threads the New Jersey Highlands, and descends into the New York metro. Weather hazards are dominated by snow squalls in the Pennsylvania Mountains and chronic congestion through the Lehigh Valley and the NJ approaches.
- Crosses three states: PA, NJ, NY (terminates at NY/NJ line)
- Primary NYC truck approach from the west
- Lehigh Valley segment is a major distribution hub for Amazon, FedEx, UPS
- Concurrent with I-81 briefly near Harrisburg
- Toll-free across most of its 144-mile length
- Eastern terminus at the Holland Tunnel approach
- Crosses the Blue Mountain ridge in eastern PA
- Entire ~77-mile PA mainline (I-81 to the PA/NJ line) is on the federal Primary Highway Freight System (FHWA)