Looking for some guide for train game

Hey,
I'm trying to build a train game which the train can ride only on the rail that I'll draw.
A friend show me how to do it with raycast so the station will transmit to the next stations were the train suppose to drive but it doesn't meet my requierments because the angels and distances are very stricted and I'm looking for something more flexible in order to build rails without tracking the grid of raycast.
I'll be glad if you can give me link to tutorial or referance to another way to build such thing.
bear in mind that there are few rails and you can switch between them...
Thanks.

BTW- I'm a novice take it under consideration when you reply