Metro serves Washington, D.C., as well as several jurisdictions in the states of Maryland and Virginia. In Maryland, Metro provides service to Montgomery and Prince George's counties; in Virginia, to Arlington, Fairfax and Loudoun counties, and to the independent city of Alexandria. The system's most recent expansion, which is the construction of a new station (and altering the line), serving Potomac Yard, opened on May 19, 2023. It operates mostly as a deep-level subway in more densely populated parts of the D.C. metropolitan area (including most of the District itself), while most of the suburban tracks are at surface level or elevated. The longest single-tier escalator in the Western Hemisphere, spanning 230 feet (70 m), is located at Metro's deep-level Wheaton station.[8]
In 2023, the system had a ridership of 136,303,200, or about 506,600 per weekday as of the first quarter of 2024, making it the second-busiest heavy rail rapid transit system in the United States, in number of passenger trips, after the New York City Subway, and the sixth-busiest in North America.[9] In June 2008, Metro set a monthly ridership record with 19,729,641 trips, or 798,456 per weekday.[10] Fares vary based on the distance traveled, the time of day, and the type of card used by the passenger. Riders enter and exit the system using a proximity card called SmarTrip.
^"Questions & Answers About Metro". Washington Metropolitan Area Transit Authority. 2017. Archived from the original on February 2, 2017. Retrieved January 20, 2017. What do I need to know to build near Metro property? Metro reviews designs and monitors construction of projects adjacent to Metrorail and Metrobus property...
^"History". Washington Metropolitan Area Transit Authority. 2017. Archived from the original on January 26, 2017. Retrieved January 20, 2017.