History: The New York City Subway, United States

There are a number of common platform configurations:
- On a double track line, a station may have one center island platform used for trains in both directions, or 2 side platforms, one for a train in each direction.
For lines with three or four tracks with express service, local stops will have side platforms and the middle one or two tracks will not stop at the station. On these lines, express stations have two island platforms, one for the local and express in one direction, and another for the local and express in the other direction. Each island platform provides a cross-platform interchange between local and express services. Almost everywhere expresses run, they run on the inner one (of 3) or two (of 4) tracks and locals run on the outer two tracks. In a 3-track configuration, the center express track can be used toward the center of the city in the morning and away from the center in the evening, though not every 3-track line has that express service.
- Three four-track express stations have an island platform for the center express tracks and two side platforms for the outside local tracks. These three stations are connected to major railway stations and the next station along the line is also an express station with the more common platform configuration. The purpose of splitting the platforms is to limit overcrowding by preventing cross-platform interchanges between local and express services. This occurs at Atlantic Avenue on the IRT Eastern Parkway Line (2 3 4 5 trains) with the adjacent express station Nevins Street, where the connection is to the Atlantic Terminal of the Long Island Rail Road; and 34th Street – Penn Station on both the IRT Broadway – Seventh Avenue Line (1 2 3 trains) and IND Eighth Avenue Line (A C E trains), with adjacent express stations at Times Square – 42nd Street and 42nd Street – Port Authority Bus Terminal, where a connection is available to Pennsylvania Station, one of the two major Manhattan train stations. This does not occur with the connection to New York's other major station, Grand Central Terminal, at Grand Central on the IRT Lexington Avenue Line (4 5 6 <6> trains), which has no adjacent express station.