Not all of NY subways are loop lines right? From https://en.wikipedia.org/wiki/New_York_City_Subway#/media/Fi..., I can't identify a loop line in the NY system at all, not like Beijing that has a couple (line 2, line 10), and of course Tokyo's inner city rail loop lines.

Usually, if a non-looping subways hit EOL, there will be a sweep and a rest period. Looping subways might just change drivers and keep going...well, it can suck when you are on a train that is retiring (in Beijing, they just dump you out and tell you to wait for the next train...).