Pennsylvania Route 378

Pennsylvania Route 378
Route information
Maintained by PennDOT
Length	9.555 mi[1] (15.377 km)
Existed	1971–present
Major junctions
South end	PA 309 in Center Valley
Major intersections	PA 412 in Bethlehem
North end	US 22 in Bethlehem
Location
Country	United States
State	Pennsylvania
Counties	Lehigh, Northampton
Highway system
Pennsylvania State Route System Interstate US State Scenic Legislative
← PA 377 → I-380

Pennsylvania Route 378 (PA 378) is a north-to-south road in Lehigh and Northampton counties in the Lehigh Valley region of the U.S. state of Pennsylvania. The southern terminus is at PA 309 in Center Valley. Its northern terminus is at U.S. Route 22 (US 22) in Bethlehem. The route heads north from PA 309 as a two-lane undivided road through Upper Saucon Township and Lower Saucon Township before crossing South Mountain into Bethlehem. Here, PA 378 follows city streets through Bethlehem's South Side, intersecting the northern terminus of PA 412. The route becomes a four-lane freeway and crosses the Lehigh River before continuing north to US 22. PA 378 is the only highway from US 22 to Center City Bethlehem, and a quick route for visitors traveling to the Wind Creek Bethlehem casino resort on the city's South Side.

The portion of PA 378 south of Bethlehem was originally numbered as PA 12 in 1928 and renumbered to PA 191 in 1961. Construction on the freeway from West Broad Street to US 22 began in 1966 and finished two years later. This freeway was numbered Interstate 378 (I-378) and served as a spur of I-78, which formerly ran along the US 22 freeway.

When I-78 was rerouted from US 22 to south of Bethlehem, the spur became disjointed from its parent. I-378 was downgraded to state route status in 1971. Three years later, the PA 378 designation replaced PA 191 from Center Valley to Third Street in Bethlehem. The state did not remove the exit tabs for the freeway section, making PA 378 one of only a few state freeways with exit numbers; another such freeway is PA 309 in Wilkes-Barre. The exit numbers also go in the wrong direction: Exit 3 is south of Exit 1, most likely due to the freeway being built when Pennsylvania still practiced sequential exit numbering. In 2009, the portion north of Lehigh River was named the Fred B. Rooney Highway after Fred B. Rooney.^[2]