 As US 19 Truck enters the southern parts of Pittsburgh, its name becomes West Liberty Avenue as it passes through the Beechview neighborhood.At the south portal of the Liberty Tunnel, US 19 Truck interchanges with Pennsylvania Route 51 (Saw Mill Run Boulevard) and joins it, following it north.After , US 19 Truck and PA 51 encounter the Penn–Lincoln Parkway, carrying I-376/US 22/US 30, at a complex, unorthodox interchange complex that stretches roughly half a mile along the Parkway and rests just south of the Fort Pitt Tunnel.