The reality is that most of the housing stock and most of the land area of America’s metros is made up of relatively low-density suburban homes. And a great deal of it is essentially choked off from any future growth, locked in by outmoded and exclusionary land-use regulations. The end result is that most growth today takes place through sprawl.
While urban densification can house some people—mainly affluent and educated ones—the bulk of population and housing growth is shifted farther and farther out to the exurban fringe. That leads to more traffic and longer commutes, and the social and environmental consequences that flow from them, as this old suburban-growth model is stretched beyond its limits.