Every large U.S. city has one or two more or less walkable neighborhoods. My last two apartments in St. Louis had walkscores of 84 and 93, respectively. But St. Louis is not walkable in any general sense and neither are most of the cities you listed.

Neither is most of the Bay Area.

I went to a CocoaConf in Austin two years ago. I snapped a lot of desire path photos, because my daily walk from my hotel to the conference was mostly devoid of pedestrian facilities, including even sidewalks.

http://m.imgur.com/a/NhaYH

Clearly, people are walking there, but the city doesn't seem to give a shit.

TIL desire path

I mean, if you live and work downtown it's pretty alright.

But then you don't really have easy walkable access to Burnet, East Side, SoCo, etc. I mean, you get 6th. Maybe Rainey depending on where you live downtown.

But yeah, I lived halfway to Bee Cave and worked on 360. That made me much happier than being directly downtown.

I live in Austin (central, Hyde Park area) and walk, bike, or bus everywhere.

Those are probably the only two cities on that list which would be (relatively) doable without cars. Pretty good public transit and significant areas that are fairly dense.

Not New Orleans. Like any city, you can identify areas where you might live and work without a car but you're going to have pretty limited mobility. Public transit is somewhat better than it used to be but it's still fairly limited--now a variety of streetcars but no subway for obvious reasons.

Chicago, Denver, Austin and, say, Santa Fe are "fly-over country"?

I think you misunderstood the term, it's loosely geographical, and more geopolitical.

HN is, as always, not the perfect avenue for sarcasm.

And yes, I've heard people refer to the Midwest as "fly-over" country, ignoring specifically Chicago, Denver, Austin, Houston, and Dallas.