 In the 1960s a automated guideway transit system was planned fanning out to the north, south, east, southeast and west including connections to both the Pittsburgh International Airport the Allegheny County Airport, Monroeville Mall and adjacent to Kennywood Amusement Park.The modern subway/light rail system can be traced to the abandonment of the proposed "Skybus" system in the mid-1970s, and the subsequent $265 million federal grant on May 7, 1979, for construction of a downtown subway and modernization of suburban light rail.PAT, working with community representatives and government officials, undertook a detailed study on the future of the South Hills trolley lines, resolving to transform these valuable, high-density transit corridors into a modern LRT system.