List of bridges of Pittsburgh
The Bridges of Pittsburgh play an important role in the city's transportation system. Without bridges, the Pittsburgh region would be a series of fragmented valleys, hillsides, river plains, and isolated communities.
A 2006 study determined tha ...
Tunnels
A tunnel is an underground passageway, dug through surrounding soil, earth or rock, and enclosed except for the entrance and exit, commonly at each end. A Pipeline transport, pipeline is not a tunnel, though some recent tunnels have used ...
Pittsburgh
Pittsburgh ( ) is a city in the Commonwealth (U.S. state), Commonwealth of Pennsylvania, United States, and the county seat of Allegheny County, Pennsylvania, Allegheny County. It is the most populous city in both Allegheny County and Wester ...