Well in Civ 5 railroads take a long time to build and have a respectable upkeep cost, so I don't think you'll see many games where they're everywhere. Playing an odd game right now but I've only got 3 lines (connecting my 3 cities to the capital) and nothing else.
My friend preordered it for me for my birthday but I haven't played as them yet. I've seen them be kind of sad in one game, but in another game they conquered everyone but me.
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