Enviro-Planning that doesn't work

With a background in planning I have always wondered will the TND's and New Urbansim turn out to be false dreams as in Paolo Soleri's Arcosanti.....

"Arcosanti was never intended as a full-scale arcology. Rather, it was to be a small model, eventually becoming home to 5,000 people. It would include a common area, composed of an open-air theater, shops, offices, and parks under a soaring, 25-story half-dome. The half-dome would have a hivelike structure in which residents would live in little honeycomb-style apartments. The whole thing would take up no more than 25 acres, surrounded by thousands of acres of empty Arizona landscape.

But today, after nearly 40 years, just a few buildings of the common space have been built, and those are gray, leaky and crumbling. On the chilly December day when I visited recently, there were maybe 50 people there, and there are never, even in good weather, more than 100 or 150 inhabitants, mostly students who come to learn about Soleri's radical environmental and architectural ideas."