I was playing a d+1 game where I (predictably) missed the collosus. Luckily, it was built in a decent city by a (now) republic. So I sent my caravans there, but what should I do once flight rolls around, and diminishes the trade. When I own collosus, I can build superhighways, but I cannot build superhighways in a comp's city, and I cannot make it grow to a large size. Should I start to do something now, or deal with the problem when it comes?