The Philadelphia Suburban Transportation Company was an operator of buses, streetcars, and a high-speed line, heavier than light rail, but lighter than commuter rail, from Philadelphia, Pennsylvania to many of its western suburbs. It was incorporated in 1936 as a successor to the Philadelphia & West Chester Traction Co., taking over as well several leased companies (including the Ardmore & Llanerch Street Railway and the Philadelphia & Garrettford Street Railway Co.) and its bus subsidiary, Aronimink Transportation Co..