The structure of America being car dependent is that the "youths" who mayor Bloomberg recently commented commit 95% of murders don't have cars or gas money to get there. The car dependent lifestyle is to create areas where undesirable elements are excluded.

In many areas "youths" gather in shopping malls and so forth and generate a lot of petty crime, vandalism, shoplifting, playing loud music and generally making everyone uncomfortable. Dead malls and downtowns have declined because of excessive presence of "youths". For example, Halloween in San Francisco's Castro got cancelled permanently because "youths" showed up and started shooting at each other. If you make it hard to get places, these "youths" tend to not show up and keep everything nice, peaceful and upscale.

Without the "youths" problem, America would have a far lower homicide rate and public transit, bikes, walkable neighborhoods, free public festivals and all that stuff would be far more popular.