125th Street (IRT Lexington Avenue Line) - IRT Lexington Avenue Line Platforms

IRT Lexington Avenue Line Platforms

The station is unique in design. It is a bi-level station, with an island platform on each level, but is not configured in the standard express-local lower-upper configuration (which is used in most stations south of this point). Instead, the upper platform serves northbound (uptown) trains and the lower level serves southbound (downtown) trains. North of the station, just after crossing the Harlem River, the line splits into the IRT Jerome Avenue Line (heading north) and the IRT Pelham Line (heading east). On the lower platform, each track comes from one line, and a flying junction south of the station allows trains to be diverted to the local or express track.

There is an active tower at the north end of the upper platform; it is a satellite to the tower at Grand Central – 42nd Street, which controls the entire length of the Lexington Avenue Line. This station's renovation was completed in 2005.

The location is referenced in The Velvet Underground song "Waiting for the Man," in which the song's protagonist uses the train station en route to buy heroin in Harlem : "...up-to Lexington, 1-2-5 ; feel sick and dirty, more dead than alive ..."