I have heard that Pittsburgh has more bridges than any other city in the world. Pittsburgh is composed of a large number of small communities that are unified by the city's bridges. It is appropriate to consider greater Pittsburgh as consisting of Allegheny County. Next there is the issue of ownership.
Various authorities have ownership of individual bridges in the Pittsburgh area.
This does not include railroad bridges. No matter how ya' cut it, there are a heck of a lot of bridges in Pittsburgh. This information was kindly provided by Mr. Ron Todorowski of PennDOT District 11-0 .