Cities are coming back across the US for many reasons. The unsafe, dirty urban core of legend is being replaced by funky, hip neighborhoods with character and charm. Life in the city can be good, now that the perma-haze of pollution has been tamed. Transit helps make life more relaxing and even cheaper. Young people in particular find revitalized cities to be affordable and great places to meet their mate and then raise kids.
The movement owes a lot to New Urbanism, junking the old industrial model for cities as centers for jobs and emphasizing attractive, functional places to live. We’ve learned a lot. But if there is one flaw in this model it’s the constant emphasis on higher and higher density. There’s always a place for high density in the urban world, of course, but it doesn’t work everywhere.
A better way to look at what makes cities great is a model based on the density gradient – a gradual increase towards the core that is economically and aesthetically sustainable.