People in the midwest are pretty bad about it. In my experience, most will avoid starting up conversations. Sometimes if you're not too creepy they'll go with it, though. The south was a lot better about having random people just talk to you really friendly, though I think it also helps to be (or at least be perceived as) as WASP in those situations.

I talk to everyone about everything when I'm drinking. Maybe everyone should just be more drunk when they're in public.