There's strong social pressure enforcing a first-come, first-serve rule on seats and standing room. Seats are only surrendered for the pregnant or disabled, and standing room is only surrendered if a child pushed his way onto a train but his parent or guardian didn't quite make it.
In other cities, I've seen people ask for spots on an otherwise full bus or train because they were running late. That would be unheard of in a NYC subway.
Do people really have to wait _hours_ for a spot on a train?
New Yorkers may exaggerate from time to time. But I have been at the 1st Avenue L stop during the morning rush and had to let 3 trains go by before getting on to the fourth (probably 20 minutes total waiting). I probably should have walked at some point but then I would have had to pay again at Union Square.
1st Ave L is probably one of the most crowded stops in the morning for rush hour in the city, probably competing closely with Lorimer and Bedford L stops.
In PM out of the city Union Square is similarly packed, and the train is nearly empty once you pass Lorimer
When I lived in Chicago, the State Street Subway at evening rush hour would have every car packed literally sardine tight. They could barely close the doors and there was barely room to breathe, forget about sitting down. I'm sure it was illegal but the conductors seemed to just pack people on until there wasn't room for one more.
Do you mean ask people to move in? Or actually ask that someone gets off for them?