New York City Subway

The New York City Subway is a rapid transit system owned by the City of New York and leased to the New York City Transit Authority, a subsidiary agency of the state-run Metropolitan Transportation Authority. The New York City Subway is one of the world's oldest public transit systems, one of the world's most used metro systems, and the metro system with the most stations and the most trackage. It offers rail service 24 hours per day and every day of the year.

The New York City Subway is the largest rapid transit system in the world by number of stations, with 469 stations in operation (422, if stations connected by transfers are counted as single stations). Stations are located throughout the boroughs of Manhattan, Brooklyn, Queens, and the Bronx. While Staten Island does have a rail line, the Staten Island Railway, it is not officially considered part of the subway, due to its lack of any direct rail link with the subway system, so any passengers wishing to reach another borough must take a ferry or bus. The Port Authority Trans-Hudson and the AirTrain JFK, in Manhattan and Queens respectively, accept the subway's MetroCard but are not part of the subway; thus, free transfers are not allowed.