List of bus routes in Pittsburgh

The Port Authority's bus system covers Allegheny County, and its service extends into small portions of neighboring Beaver, Butler, and Westmoreland counties. These counties also have their own transit systems, including several routes that run into Downtown Pittsburgh, where riders can make connections with Port Authority service.

From 1964 to 2010, the Port Authority used an alphanumeric numbering system. With the renumbering and realignments outlined in the Transit Development Plan in 2009, the present numbering system was adopted in April 2010.

Light rail and busways are designated by the following colors:

As a result of the Transit Development Plan and a series of service cuts, many routes have been reworked or eliminated.

Bus routes that are discontinued from the lineup and integrated into other one or more route(s) throughout PAT's history include:

Port Authority operated special park and ride shuttles to Steelers' games and other stadium events from 1967-2011. Routes with an "S" were for servicing one time events.

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