To pass time waiting for new troops to be trained, I've been building roads all over the island. It struck me that it would be nice to have them actually do something - an obvious idea is to shorten the travel time from production to storage (and maybe resources). Of course, there would also have to be some sort of cost involved, otherwise you'd just pave your island with roads

There could then be further enhancements with ox-carts and whatever. I expect this isn't going to be high on the list of coding priorities, but it would make the game more... OK not 'realistic' as such, but maybe give it a nudge closer to role-playing. And it wouldn't have to unbalance the game, as long as the speed advantage isn't too big.