The
Pittsburgh Light Rail (commonly known as
The T) is a
light rail system in
Pittsburgh,
Pennsylvania; it functions as a
subway in
Downtown Pittsburgh and largely as an at-grade light rail service in the suburbs south of the city. The system is largely linear in a north-south direction, with one terminus just north of Pittsburgh's central business district and two termini in the
South Hills. The system is owned and operated by the
Port Authority of Allegheny County. It is the successor system to the streetcar network formerly operated by
Pittsburgh Railways, the oldest portions of which date to 1903. The Pittsburgh light rail lines are vestigial from the city's streetcar days, and is one of only three light rail systems in the United States that continues to use
Pennsylvania Trolley (broad) gauge rail on its lines instead of
standard gauge. Pittsburgh is one of the few North American cities that have continued to operate light rail systems in an uninterrupted evolution from the first-generation streetcar era, along with
Boston,
Cleveland,
New Orleans,
Newark,
Philadelphia,
San Francisco and
Toronto.