Smart trains need to come to a stop in about a half mile...They don't stop on a dime...Any fool who wanders on the tracks is going to pay for it....Stopping on a dime means passengers bouncing around in the coach like a rubber ball, its means flat wheels and the engineer gets to watch the trespasser get chewed up. Ed. Workman spelled it out right. Common sense needs to be used if the person in doubt has any.