I've been thinking about this for a while... I don't know how well it could work, or even if a game using this would remain "civ", but I think it solves (or at least reduces) the problem that we get late in the game of having hundreds of units to move over thousands of game tiles.
Basically, make all of the tiles within the cultural boundry of a city count as one tile for the purposes of unit movement (simulating improved infrastructure around big cities), and allow army stacks as in the total war games. Also, for the sake of ballance, a units turn would have to end once it entered a city's boundry. So not only would this reduce the number of unit moves, but also the number of combats per turn - surely a good thing!
This idea also suggests some other changes:
-Workers be replaced by some sort of automatic tile improvement system, or even something similar to CTP. I personally would like to see an automatic tile improvement system implemented - less micromanagement please
-The city radius be replaced by it's cultural influence. Basically, as your city grows more culturally important, it also becomes more economically important to the surrounding countryside. It also gives the cultural radius the feeling of a province.Seems logical to me.
-Sea tiles within a city's influence (not divided by land) become a single square for the purposes of movement (simulating a better understanding of familiar waters). Not only will this speed up ships somewhat, but it will also simplify blockades.
-Possibly a total war style real time battle system? I realise this would be most difficult/unlikely, but would be a cool addition, imo.
Basically, make all of the tiles within the cultural boundry of a city count as one tile for the purposes of unit movement (simulating improved infrastructure around big cities), and allow army stacks as in the total war games. Also, for the sake of ballance, a units turn would have to end once it entered a city's boundry. So not only would this reduce the number of unit moves, but also the number of combats per turn - surely a good thing!
This idea also suggests some other changes:
-Workers be replaced by some sort of automatic tile improvement system, or even something similar to CTP. I personally would like to see an automatic tile improvement system implemented - less micromanagement please

-The city radius be replaced by it's cultural influence. Basically, as your city grows more culturally important, it also becomes more economically important to the surrounding countryside. It also gives the cultural radius the feeling of a province.Seems logical to me.
-Sea tiles within a city's influence (not divided by land) become a single square for the purposes of movement (simulating a better understanding of familiar waters). Not only will this speed up ships somewhat, but it will also simplify blockades.
-Possibly a total war style real time battle system? I realise this would be most difficult/unlikely, but would be a cool addition, imo.