The thing that bugs me about the indictment of suburbia is that it's often painted with a (biased) general brush. I used to rent in a suburb that was on the city transit line, and was more like an extension of the city. I also grew up in a quiet suburb that was on the train line, had a small central uptown, and I walked everywhere- to school, the library, parks. My mom biked to get groceries. I'd rather be in a suburb like that than a more crowded city should things disintegrate. Isolated, car-culture suburbs are not at all ideal, but around here they're often cheaper too, which is why I guess some people choose to live there. But not all of "suburbia" is subdivision urban sprawl, so I guess when some people go on about the "suburbs" the generalizations get on my nerves a bit.
The second kind, that's what Kunstler is saying will degenerate into slums, because you can only navigate them by car. Or maybe horse. Will we have horses in this Long Emergency?
I'm a geek for town planning, but sometimes I like to think of how we would reuse Wal-Marts and exurb gated communities come the apocalypse.