Supertrain is an excellent show. Took my grandson there a few years ago. (Hint: take a little plastic chair/stepstool for the kids - does wonders)
I hope the Calgary Model Trainmen still have their 2' x 8' Timesaver switching layout that the kids can operate. My handiwork from about 15++ years ago.
When we first displayed this layout for the kids to operate, it was complete chaos. We solved the problem by making the kids form a line & while one kid was operating the layout, we gave the next-in-line a 6" x 12" sign that said "I'M NEXT". (This was proudly displayed to waiting parents). No more arguments about whose turn it was! When the time came, the sign was cerimoniously handed off to the next in line.