In 1971 the city of Bolinas, California, stopped growing. Why? Because that was the year the city decided to stop allowing new water meters to connect to the city supply. And no new water meters means, for practical purposes, no new houses — ergo, no more growth. You can see that in graphical terms via Trulia, with the city’s growth essentially hitting a wall in 1971.
For practical purposes, the city hit a resource wall. No more water. Granted, that wall was externally created — via legislation — but the effect was the same: a resource constraint changed the evolving nature of a city.
Something similar has to happen with $5/gallon oil across the U.S., and it has to become even more pronounced at $7 oil, etc. Cities’ structures will change, with most hitting an "exurbification" wall in 2008. Just look graphically at the evolution of cities like San Diego or Atlanta to see a pattern that will not be repeated in future.
More here on Bolinas and its "no mo’ meters" decision from a 2005 piece in the NYT.