Look, I should be quick so JSE fans don't make you lose this community post. Also, I don't know if you're going for a realistic approach or not so here: The idea is a teleporter rail. when the train goes in, it comes out of another teleporter of the same colour. also, it has an optional 2 second cooldown, so if you're planning on making a feature of multiple trains, you could make a complicated mess where one train goes in and another one goes through so it could go on a different path then the teleported train.
Quick track idea.
I think the teleporters should be like tunnels. If you wanted to make them connected, you could place tunnel blocks that make it look like it's connected out there. And if you didn't connect it with the tunnel blocks, the tunnel would look like it's going underground and the end part of it would look like it's coming up. Teleporters that look like tunnels would really be nice since the game is about trains.