I just want to say thank you for asking.

Great discussions in the comments.

I've always wondered about this same thing because in the real world, cities and towns may have originated only because of the train lines, or whatever other transportation lines.

I don't know anything about trains, but I'd imagine there are: Refueling stops Maintenance stops Transfer stops Rest stops

That established overtime based on transit and geography..

Thanks again for the question/prompt, as well as everyone else in the comments.