I've been to fire island, which is the only truly car free place I've ever visited. I remember feeling great not to have to worry about being run over by some over anxious motorist in a hurry to get somewhere. I live in NYC and haven't owned a car in 12 years--though biking here is hardly a breeze. I think its feasible that most of NYC could be made car free someday. We already ahead of most U.S. cities in that we've got a developed public subway/bus system that people rely on.