Duplo - Intellitrain

Thèses 2 parts allow the train to stop (dual signal) or to go reverse (one way or the other).
You just need to put it on the rail. (the new ones, the grey ones, not the old black ones).
Source sketchup provided.
Feel free to modify.
It's not a full remix as I have made it from scratch, but the main idea goes to the original design.
Have fun.
Need support !