With an average weekday ridership of 764,300, the Washington Metro is the second-busiest rapid transit system in the United States behind the New York City Subway.
[2] Construction began in 1969, and in 1976 the first section of the Metro system opened along the Red Line between the Farragut North and Rhode Island Avenue stations in Washington, D.C.
The system, as originally planned, was completed in 2001 with the extension of the Green Line to Branch Avenue.
[4][5] On the Yellow and Blue Lines, an additional infill station at Potomac Yard opened on May 19, 2023.
[7] The busiest station in the system in 2023 was Metro Center, with more than 3.9 million passenger entries over the course of the year.