The mechanism of the switch is not the impressive part. The impressive part is that the train stays in motion the whole time (and not at an insignificant speed). Consider on Hagrids how short of a distance and how short of time the ride would have to stop the train should the switch not move and relock in the time between when the train fully passes the switch, accelerates to the launch, stalls, then reverses over the switch. On Everist and Grizzley, the train comes to a full stop (or is on a lift hill which could be easily stopped if necessary) while the switch track locks. If there is an issue with the switch, the computer just keeps the train stopped... no biggie. Hagrid stays in continuous motion. The safety mechanisms need to monitor the train and the switch to ensure the switch moves and locks before the train hits a point of no return where the safety system couldn't stop the ride . The safety mechanisms and sensors that need to go into that feat are pretty crazy...