The Washington D.C. METRO is the rapid transit system serving the Washington metropolitan area. It is administered by the Washington Metropolitan Area Transit Authority, which also operates Metrobus service under the METRO name. The METRO system has six lines and 91 stations, providing service to the District of Columbia, as well as parts of Maryland and Virginia. The METRO system is the second busiest rapid transit system in the United States in terms of ridership, after the New York City Subway.