I kinda agree with Porkie, end of the day, you can't swerve out the way like you can in a car... you're on a contant bearing and if someone chooses to place themselves in the way, its out of your control to a great extent.
Alright, you might say you can slam the brakes on, but this would possibly cause problems with your passengers.... and maybe cause serious problems with the train? I dunno, but would slamming your brakes on cause a possible de-rail situation?
That said, if you think about it for too long and get into the whole "I killed someone" thing.. then I'm sure it must put you in a pretty dark place. Is there no help/time off given to drivers who go through this?
Cheers,
Grant