New-york City subway

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. In addition, the Staten Island Railway does not connect to any other trains, so any passengers wishing to visit another borough must take a ferry or bus.

Almost all routes pass through Manhattan (except the G, Franklin Avenue Shuttle and Rockaway Park Shuttle trains), and all but five of the 468 stations are served 24 hours a day. Contrary to its name, the New York City Subway system is not entirely underground. Large portions of it (especially outside Manhattan) are elevated, on embankments, or in open cuts, and a few stretches of track run at ground level. In total, 40% is at or above ground.

Many lines and stations have both express and local services. These lines have three or four tracks. Normally, the outer two are used for local trains, while the inner one or two are used for express trains. Stations served by express trains are typically major transfer points or destinations. The BMT Jamaica Line uses skip-stop service on portions, where two services (J and Z trains) operate over the line during rush hours in the peak direction and many stations are only served by one of the two.

In 2005, the New York City Subway hit a 50-year record in usage with a ridership of 1.45 billion. The trend toward higher ridership continued into 2008.

The Citizens Budget Commission reported in 2011 that the subway system was among the most cost-efficient in the country, with the lowest cost per passenger trip and second-lowest cost per passenger mile.

A demonstration for an underground transit system in New York City was first built by Alfred Ely Beach in 1869. His Beach Pneumatic Transit only extended 312 feet (95 m) under Broadway in Lower Manhattan and exhibited his idea for a subway propelled by pneumatic tube technology. The tunnel was never extended for political and financial reasons, although extensions had been planned to take the tunnel southward to The Battery and northwards towards the Harlem River. The Beach subway was demolished when the BMT Broadway Line was built in the 1910s; thus, it was not integrated into the New York City Subway system.

The New York City Transit Authority, a public authority presided by New York City, was created in 1953 to take over subway, bus, and streetcar operations from the city, and placed under control of the state-level Metropolitan Transportation Authority in 1968.

The September 11th attacks resulted in service disruptions on lines running through Lower Manhattan, particularly the IRT Broadway – Seventh Avenue Line, which ran directly underneath the World Trade Center between the Chambers Street and Rector Street stations. Sections of the tunnel, as well as the Cortlandt Street station, which was directly underneath the Twin Towers, were severely damaged by the collapse and had to be rebuilt, requiring suspension of service on that line south of Chambers Street. Ten other nearby stations were closed while dust and debris were cleaned up. By March 2002, seven of those stations had reopened. The rest (except for Cortlandt Street on the IRT Broadway – Seventh Avenue Line) reopened on September 15, 2002 along with service south of Chambers Street