IRT Second Avenue Line

The IRT Second Avenue Line, also known as the Second Avenue El, was an elevated railway in Manhattan, New York City, United States, operated by the Interborough Rapid Transit Company until city takeover in 1940. It ended service on June 13, 1942, although the portion north of the 57th Street closed on June 11, 1940, with the city takeover.

In 1875 the Rapid Transit Commission granted the Gilbert Elevated Railway Company the right to construct the railway from Battery Park to the Harlem River along Second Avenue. The commission also granted the Gilbert Elevated Railway Company the right to operate the Sixth Avenue Elevated and soon afterward the Gilbert Elevated Railway change its name to the Metropolitan Elevated Railway.

As part of the Dual Contracts, this line was triple-tracked, allowing true express service.

The Second Avenue El did not run entirely on Second Avenue. Its southern terminus was City Hall, and it continued to Chatham Square, where it split off from the Third Avenue El and ran along Division Street and then Allen Street. At Houston Street it ran north on First Avenue, where it turned left on 23rd Street ran north on Second Avenue to 129th Street. At that point it joined with the Third Avenue El and crossed the Harlem River into the Bronx.

The M15 bus, which runs along much of the IRT Second Avenue Elevated Line's route, carries more passengers than any other route in New York City. However, it does not carry as many passengers as a rapid transit line, and does not allow for interchange within rapid transit stations. A replacement rapid transit route, the Second Avenue Subway has been under consideration since before the demolition of the IRT Second Avenue Line, and is under construction as of 2012. The first phase is scheduled to open in 2016.