Sprawl is malfunctioning. It has underperformed for decades, but its collapse has become obvious with the recent mortgage meltdown and economic crisis, and its abundance magnifies the problems of its failure.
Let us be clear that sprawl and suburbia are not synonymous. There are many first-generation suburbs, most of them built before WWII, that function well, primarily because they are compact, walkable, and have a mix of uses. Sprawl, on the other hand, is characterized by auto-dependence and separation of uses. It is typically found in suburban areas, but it also affects the urban parts of our cities and towns.