Moonman is right: there are always "touchers." I think it is just the nature of inquisitive, learning minds. We have tried some ways to address the issue. Sometimes I will stop the trains, and say: "Touching trains when they are moving can cause a wreck, do you want to touch them now with one finger?" Of course, even that sometimes doesn't work. I try to keep smooth-roof passenger trains on the outside. No raised pantographs or other easy-to-snag obstructions. One question that a student asked today was "how do the trains stay on the track?" Great question! We stopped, took a car and turned it over, and let all of them touch the flange, showing how that kept the trains on the track.
I know this is not for everyone. Heck, if I had a vision-line Big Boy I wouldn't take it here either. But, this is part of making trains more available and understandable to kids.
All I can say for me this is great fun.
