He is on private property and trespassing. He can be both fined and arrested just for being there. If you are operating the train and you are the one hitting idiots all the time because you can't swerve, you might have a different attitude... particularly after yelling at some dumb ass kid to get away from the tracks as you approach and he refuses to do so.
Trespassing along railroad rights-of-way is the leading cause of rail-related deaths in America. Nationally, more than 430 trespass fatalities and nearly as many injuries occur each year. The vast majority of these are preventable. Most railroad trespassers are pedestrians who use railroad tracks as a shortcut.