High Quality Content by WIKIPEDIA articles! The Washington Metro, commonly called Metro, and unofficially Metrorail, is the rapid transit system in Washington, D.C., United States, and its surrounding suburbs. It is administered by the Washington Metropolitan Area Transit Authority (WMATA), which also operates Metrobus service under the Metro name. In Maryland, Metro provides service to Montgomery County and Prince George`s County; in Virginia, to Fairfax County, Arlington County, and the City of Alexandria. Since opening in 1976, the network has grown to include five lines, 86 stations, and 106.3 miles (171.1 km) of track.