Originally posted by a_wanderer
i think perhaps the best solution is that the railway network of the country should have a 'total capacity', based on perhaps the lenghth of the network (the longer the greater the capacity) or why not ammount of money spent on 'transportation' (i.e. you put in 1 gpt in transportation - you get 10 trasport capacity, - 2 gpt = 20 transport capacity etc). the capacity itself should be distributed as a player seems fit. for example if you have 10 transport capacity - they you can choose to move a single unit 10 squares distance, or you can choose to move two units each of them for 5 squares of distance, etc. - the idea is that one unit of transport capacity should allow one unit to move one square.
I think it sounds good, better than having a fixed maintenance cost for railways

What if instead of buying transport capacity and using it up during transport just move an unit and loose the according amount of money? Basically the same but makes it easier.
Additionally I would like to have railway stations, since you definetly need some infrastructure to load large amounts of troops and material.
If you want to be able to transport troops by railway not only between cities, what about railway stations as tile improvement? After all, workers can build airports, too...
