History: The New York City Subway, United States

A typical subway station has waiting platforms ranging from 500 to 600 feet (150 to 180 m) long. Due to the large number of transit lines, one platform or set of platforms often serve more than one service. Passengers need to look at the overhead signs at the platform entrance steps and over each track to see which trains stop there and when, and at the arriving train to see which one it is.
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.