I would love to see a city in the Western parts of the US accomplish this mainly because of how difficult of a task it would be. The majority of people live >15 miles from downtown areas. Mass transpo can only be generously described as an after thought. I've played SimCity, and if you did not place your subway/train/bus stops efficiently, the citizens did not use them. That plays out in real life as well, except it is much more difficult in real life to just break out the bulldozer to re-engineer the city to make it more mass transpo friendly.
