The room looks awesome! One lucky kid to have that in his room.
Based on the door height, I'm guessing that the shelf is about 8' off the ground?
If you don't mind sharing, I would be interested to know what the "rules" are for running the train in your situation. I ask because I am in a similar situation with young kids at home. I want them to have fun with the trains but I don't want their inner "kid" to see how fast they can destroy them either.