prewalk

Verb. When using a subway system, to prewalk is to use the time while waiting for a train to walk to the spot on the platform where you will board the train so that when you get off the train at another station, you will be at a desired location on the platform, e.g. stairs, turnstile, or corridor to another train.

Noun. The walk required to get to a desired spot on a subway platform as described above.

To position oneself on a subway platform such that, when the passenger steps off the train at his destination, he'll be as close as possible to the exit or stairs to his transfer. Used and done often in the nyc subway system.