A possible compromise (for Civ 4 perhaps...) would be to still allow infinite railroad movement, but units would only be able to use them to travel from city to city. That is, you'd have the unit board the rails in one city, and get off in another.
To move units to tiles other than city centres, units would have to use roads. Speaking of which, when "motorized transport" (or "automobile" or whatever...) comes around, roads could be upgraded (by workers) to "highways" which could provide a further increase in movement over roads (say, 1/6 or 1/9 of a movement point per 'highway' tile).
To move units to tiles other than city centres, units would have to use roads. Speaking of which, when "motorized transport" (or "automobile" or whatever...) comes around, roads could be upgraded (by workers) to "highways" which could provide a further increase in movement over roads (say, 1/6 or 1/9 of a movement point per 'highway' tile).
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