 The 47S line was established in an effort to relieve congestion on the Red Line for the additional traffic that the parking garage created.The Blue Line - South Hills Village route follows the South Hills Village leg of the Red Line and the common leg from Washington Junction to Willow Station, which is adjacent to Overbrook Junction, where it switches to the Silver Line mainline.It follows the Silver Line to South Hills Junction where it reunites with the Red Line before entering downtown.