Interstate 78 travels 75 miles east from I-81 in Lebanon County to Allentown, Bethlehem and Easton as part of a 143 mile route joining the Harrisburg area with Newark, New Jersey and New York City. I-78 replaced four lane sections of U.S. 22, including the Lehigh Valley Thruway through Allentown-Bethlehem for a period of time. U.S. 22 remains overlapped with the freeway from Hamlin (Exit 8) east to Chapman (Exit 51).
Interstate 78 Pennsylvania Guides
A new alignment for Interstate 78 south of the Allentown-Bethlehem area was proposed by the early 1980s. When it opened on November 21, 1989,1 I-78 was fully complete in the Keystone State. The realignment of the freeway mainline away from the Lehigh Valley Thruway (U.S. 22) disconnected Interstate 378, a freeway spur into Downtown Bethlehem, from I-78 with it subsequently redesignated as Pennsylvania Route 378.
 scenes |
 | PA 412 (Main Street) heads north from the borough of Hellertown to a folded diamond interchange (Exit 67) with Interstate 78 along the Bethlehem city line. PA 412 advances north along Hellertown Road to Northampton Heights and E 4th Street. 04/23/04 |
 | Morgan Hill Road (SR 2005) north meets Interstate 78 at the easternmost interchange in Pennsylvania opposite Philadelphia Road into the city of Easton. 09/01/05 |
Photo Credits:
04/23/04, 09/01/05 by AARoads
Connect with:
Interstate 81
Interstate 476
U.S. 22
U.S. 222
Route 61
Route 309
Route 611
Page Updated 01-19-2021.