Yes you can do that, but just to make sure this is a simple tutorial, which is easy and understandable, I did not make it complex using collision groups, however once you got to know how this basic train works, you can make your custom train, so I did not include the hard ones here
Look try to keep it full touched to rails, then you notice, the train won’t move
The reason, I told to keep 1 stud is, when changing track, or turning of train, the 1 stud space gets filled and then it turns smooth as you see in the video at last
Why not 2 studs space?
As you know weight = mass * gravity
Roblox physics have gravity and mass, now if you keep 2 studs gap, the weight on the right side of the train increases, center of mass chages, and the train de-rails, or turns backwards