As usually, Doug, you make an excellent point. The only thing that I would add to that article is that cars in the US is not just about transportation, but also, or perhaps even more so, about illusions of safety and being in control.
US strikes me like one of the most fear-ridden and control obsessed societies I have a chance to visit (and I traveled a bit). There are many contributing factors - extensive use of fear mongering for political and commercial propaganda, the nomadic nature of the US life which undermines stable communities, or racism to name a few. But the bottom line is that many US-ers are fearful of the "outside world" - stretching from big cities to foreign countries - and eager to take any protective measure they can find - from escaping to the burbs, to arming themselves, to installing security systems and above all driving cars which are like pods that create a illusion of safety (by insulating them form the outside world) and being in control.
The fact that US ers drive more is not just a result of land use and lack of transportation alternatives - but also of their need for security and control.
Wojtek