Don't go pushing that button unless someone is bleeding out and you gotta tell the operator to stay stopped at the next station. Yeah sure if you need to but otherwise you're gonna be standing there looking stupid talking on he speakerphone while all the other passengers are just annoyed because they don't give a F and you're wasting their time. Better off just making a discreet 911 call.

When youre taking the train at odd hours sit as close up to the front as possible. Most of the train operators are cool don't expect them to come out of their locked thing and confront the assailant but they generally have a low BS tolerance. That's the safest place to sit.