Over the past year or so, both of these forces have dramatically weakened. With credit tight and the demand for housing drying up, new construction in the exurbs is grinding to a halt. The result is a decline in the building industry's appetite for rural land on the urban edge. The question now is whether that decline will last.

Persistently high gas prices may mean that the next building boom will take place not at the edges of metropolitan areas but far closer to their cores. People are more willing to drive 20 miles each way to work every day, burning a couple of gallons of gas in the process, when gas costs less than milk. But as gas prices climb, long car commutes become a rising tax on exurban homeownership, and the price people are willing to pay for homes in remote areas will fall.

Increasing gas prices may not be enough to cause people to move, which is why demand for gas proves so inelastic in the short term, but it can influence where people choose to live when they are forced to relocate for other reasons.

The death of sprawl will present enormous challenges, chief among them the need to provide affordable middle-class housing in areas that are already built up.

Overcoming low-density, single-use zoning mandates so as to fairly allocate the costs of increased density will require coordination at regional levels. This in turn will require overcoming the balkanization of America's metropolitan areas. This shift toward a more regional outlook will force broad rethinking of how we fund and deliver services provided by local governments.

Although the end of sprawl will require painful changes, we may find that one day we won't miss our cars and commutes, and the culture they created, nearly as much as we feared we would.

• Eduardo Penalver is an associate professor at Cornell Law School, where he teaches property and land-use law.