i was in the train then left the computer for 5-10min and when i came back, the train had stopped and i couldn't get out. i had to call for help. then a helper entered and the train started to move again.
Yep, I do know this happens when we get to an instanced location like the subway or the race. In the example of a race they cannot get out of, the arrival of a staff member to assist them boots them out of the location; in your case, the train leaves the station- in those cases, we didn't necessarily do something, but our arrival kicked the process. In the best case scenarios, we'd like the subway to move when expected and that a player would not get stuck in the race.