I have to agree with >>112020-san. Trains are very interesting sophisticated mechanisms, and also a part of the very complex railroads system. The railroads are limited, so people have to figure out how to use them efficiently, avoiding train collisions at the same time. It is a very complex mathematical task to solve. That's why all MIT hax0rz were "densha otakus" in the Tech Model Railroad Club (TRMC).

Personally I never was into trains that much, but I was a member of the car modeling and ship modeling clubs back in the school days, so I do get why people love trains, and I would never ask such a question. Trains are cool.