Currently operating heavy rail rapid transit systems in the United States

California	Bay Area Rapid Transit Los Angeles Metro Rail B and D lines
DC–MD–VA	Washington Metro
Florida	Miami Metrorail
Georgia	Metropolitan Atlanta Rapid Transit Authority
Hawaii	Skyline
Illinois	Chicago "L"
Maryland	Baltimore Metro SubwayLink

Massachusetts	MBTA subway Blue, Orange, and Red lines
New York	New York City Subway Staten Island Railway
New York/New Jersey	PATH
Ohio	Cleveland RTA Rapid Transit Red Line
Pennsylvania	SEPTA Broad Street, Market–Frankford, and Norristown High Speed lines
Pennsylvania/New Jersey	PATCO Speedline
Puerto Rico	San Juan Tren Urbano

Other transit in the United States: