Yes, much less than 100 cities. I live in the Phoenix area, and can't imagine how hard it would be without a car. It's so spread out that it isn't funny. I have a car mostly because I like driving, but still would have one if I didn't, just not the same kind of car.

I also feel like a certain number of those people are carless not by choice but because they cannot afford a car, and are putting up with a pretty extreme level of inconvenience.