The West Busway is a two-lane bus-only highway serving the western portions of the city of Pittsburgh and several western suburbs. The busway runs for 5.1 miles from the southern shore of the Ohio River near Downtown Pittsburgh to Carnegie, following former railroad right-of-way on the Panhandle Route. It broke ground on October 27, 1994 and is owned and maintained by the Port Authority of Allegheny County, the public transit provider for Allegheny County and the Pittsburgh region. The transit thoroughfare was opened in September 2000. Following the naming convention of each busway being designated by a color, bus routes that use the West Busway begin with a "G" for green.
Four Port Authority bus routes currently serve the West Busway. One route is the flag carrier of the busway and terminate at the end of the thoroughfare. The G2 West Busway All Stops travels along the end of the busway to West Carson Street, crosses the Fort Pitt Bridge, then makes a loop through Downtown Pittsburgh. Another important route, the 28X Airport Flyer, uses the West Busway as far south as Bell Station; dedicated ramps connect the Busway to Interstate 376/US 22-30. Following the naming convention of each busway being designated by a color, bus routes that use the West Busway begin with a "G" for green.