Philadelphia has the fourth oldest subway system in the United States, dating back to its opening in 1907. Operated by the Philadelphia Rapid Transit Company until 1939 and the Philadelphia Transportation Company until 1968, the SEPTA subway system consists of two rapid transit systems converging in Center City, and five surface level trolley lines operated in a shared subway through downtown Philadelphia.

SEPTA Subway/Elevated
 Combined, the Market-Frankford Line and Broad Street Line have the sixth highest ridership of rapid transit systems in the United States, with a daily ridership of 289,300.[21] The rapid transit system has a total length of 25 miles (40 km) and 50 stations. Feeder trolley and bus systems connect to the terminals of the Market-Frankford Line. At 69th Street Terminal, the Norristown High Speed Line, SEPTA Route 101, and SEPTA Route 102 connect to nearby suburbs, and a large bus depot handles SEPTA suburban bus routes. Near the eastern terminus of the Market-Franford Line, three trackless trolley lines and multiple diesel bus lines converge. In addition, several regional rail lines stop at the Fern Rock Transportation Center of the Broad Street Line.
The Subway–Surface Trolley Lines are the remnants of an extensive pre-World War II streetcar system, similar to the Boston Green Line and San Francisco Muni Metro. The trolley lines were originally run by different companies, until their consolidation by the Philadelphia Rapid Transit Company in 1906.The trolleys run in a tunnel from the Drexel University and University of Pennsylvania campuses to a loop around City Hall. Unlike light rail systems with articulated vehicles, the trolley lines use vehicles closer in size to classic PCC streetcars.
PATCO Speedline
The PATCO Speedline is a grade-separated system linking Philadelphia to the cities of Camden, Cherry Hill, and Lindenwold in New Jersey. The Speedline has a daily ridership of 38,000, and is the primary transit link between South Jersey and Philadelphia. It is operated by the Port Authority Transit Corporation, a subsidiary of the Delaware River Port Authority (DRPA), and is the only rail line in Philadelphia to operate 24 hours a day. According to a study conducted by the Delaware Valley Regional Planning Commission, 95% of riders are New Jersey residents, and the Speedline carries 47% of New Jersey business commuters with jobs in Center City.
SEPTA Route 15
Main article: SEPTA Route 15
Route 15, commonly known as the Girard Avenue Trolley, was restored in 2005 after having been operated with buses for 13 years. The 15 line runs along Girard Avenue through Greater Kensington, North Philadelphia, and West Philadelphia. The trolley utilizes restored PCC streetcars, a type of heritage trolley built in the 1930s. The trolleys were rebuilt with added air conditioning and regenerative braking.The 15 line is the only active trolley line in Philadelphia which is not part of the Subway-Surface Trolley Line system.