[panic]

Instead /goals/ must be dictated, strive for X, prevent Y, co-operate with Z to prevent unwanted unintended consequences.

I don't think it's that simple. The "goals" of a city are the goals of the people living in it, which are as complicated as the city itself. Your example is actually a great illustration of how large-scale decision making can go wrong: the sprawl met someone's goals, or it wouldn't have happened, but it didn't match the needs of the actual people living in the city. In general, how do you know the goals you're dictating are the right ones? A better focus would be on ways for individuals and communities within cities to organize, communicate their needs and get resources to solve their unique problems.