SEPTA's Subway-Surface Trolley Route 13 (a.k.a. the Chester Avenue Subway-Surface Line) is a trolley line operated by the Southeastern Pennsylvania Transportation Authority (SEPTA) that connects the 13th Street SEPTA Station in downtown Philadelphia, Pennsylvania, with the Yeadon Loop in Yeadon, Pennsylvania, although limited service is available to the Darby Transportation Center in Darby, Pennsylvania. It is one of five lines that are part of the Subway-Surface Trolley system.