When housing and mobility costs are combined, the typical household can afford to live in only 28 percent of America's neighborhoods.

New urbanists have long contended that mixed-use projects are treated unfairly by the transportation-engineering establishment. The “trip generation rates” promulgated by ITE fail to recognize that when diverse uses are brought together in walkable settings, people may drive substantially less.

The potential loss of civic buildings could undercut community life in some towns.