You can't control it, a train does not stop on a dime (unless it's one placed on the track). I was talking with an old friend who spent his life in trainman service; there had been a fatality recently and I asked him if he'd ever had to deal with it. He simply said, "You never forget it."

When you are in the cab you have little to no control over the situation, you aren't the cause of it, and yet it dwells on your conscious. I have great empathy for those who have to face it.