Squash Growing On The Train Tracks?

The plant above was seen growing on the Sheepshead Bay station, close to the platform.

The plant stalks pictured to the side, though a little difficult to see is believed to be the same as the one above — except that the one above is more of a trailing vine.

The leaves look similar to pumpkin plant leaves, so could this be the growth from pumpkin seeds thrown from the subway cars by people who can’t wait for the garbage can? Or, is it a type of squash?

Are there any gardeners who might be able to identify this plant, or will we have to wait for the next harvest to check its yield?