IRT Lexington Avenue Line

IRT Lexington Avenue Line

The Lexington Avenue Line (also known as the East Side Line) is one of the lines of the IRT division of the New York City Subway, stretching from Downtown Brooklyn or Lower Manhattan north to 125th Street in East Harlem. The portion in Lower and Midtown Manhattan was part of the first subway line in New York. The line is served by 4 5 6 <6> trains.

The line is also known as the IRT East Side Line, as it is currently the only line in Manhattan to directly serve the Upper East Side and East Midtown; this four-track line is the most used rapid transit line in the United States. Its average of 1.3 million daily riders is "more than the combined ridership of San Francisco and Boston's entire transit systems".

Its ridership also exceeds that of the 798,456 daily trips on the entire Washington Metro and the 703,326 daily trips on the entire Chicago 'L' system. Construction has started on the IND Second Avenue Line to alleviate the severe overcrowding caused by the Lexington Avenue Line's high usage.

Several stations along this line have been abandoned. When platforms were lengthened to fit ten cars, it was deemed most beneficial to close these stations and open new entrances for adjacent stations. For example, 14th Street – Union Square has an entrance on 16th Street and 23rd Street has an entrance on 22nd Street, so the 18th Street station was abandoned because of the proximity to both 14th Street – Union Square and 23rd Street.

As of January 2010, the 4's fleet is both R142 and R142A cars. The 5's fleet uses R142 cars and the 6's fleet uses R142A cars.