It is a bit embarrassing to say, but I started this model back in November... 2022. It took a lot more work to get the tall lifts to work and for the whole model to run reliably. In the video I show all of the mistakes and learnings made along the way. I have tried to make it as entertaining as possible, and I hope, that you enjoy it. The model started with me wanting to see how many trains can loop or pass through the same point at the same time. A shortage of space was coming up early, and the modified loops required a lot of additional speed for the trains to clear reliably. But with increased speed, also came increased friction, and if you look closely, you can see how much the trains have deposited of red ABS on the sides of the loop tracks! The roller coaster is activated using the "color distance sensor" from LEGO Boost. This sensor is great at communicating when it can be activated, and in my field test, visitors had an easy time figuring out how to interact with the model. Some children stayed for quite some time and activated the roller coaster whenever the light shined green. Unfortunately the model was not yet reliable when it was exhibited, so it required me to be on-site at all times. This latest version should be much better for public display. Only time will tell. If it turns out to be a success at event, then I would like to make it even more complicated with more trains in the "knot". Do you have any good ideas to how to add trains without risking collisions?