I already know about that wide trains and normal trains are different object. If both are selected, then you can see wide trains first. You can see in the first screenshot.
Anyway, this is not a main problem. If both are selected, then you can see wide trains first. So I can actually use wide trains. (wide trains -> normal trains O, normal trains -> wide trains X)
Main problem is "all of normal Twister Roller Coaster's track design is in here." This is really a problem.