Why Are Americans Driving Less?

Infrastructurist has the details on some great news.  Americans are driving less, ending a steady climb in vehicle miles traveled since... well forever.

 

But it brings up an interesting question.  Is this really a change in behavior or just a reaction to increase in unemployment and reduction in discretionary trips.  Nate Silver, of FiveThirtyEight fame, takes a stab at digging into the stats.  Even though he was wrong about the Oscars, he's right about everything else.  He figures:

There is strong statistical evidence, in fact, that Americans respond rather slowly to changes in fuel prices. The cost of gas twelve months ago, for example, has historically been a much better predictor of driving behavior than the cost of gas today. In the energy crisis of the early 1980s, for instance, the price of gas peaked in March 1981, but driving did not bottom out until a year later.
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The exceptionally sluggish pace of new-vehicle sales, moreover, in the face of extremely attractive incentives being offered by the automakers might imply that Americans are considering making more-permanent adjustments to their lifestyles. And the denigration of the brand of the Big Three automakers in light of their financial difficulties — about one third of Americans have generally told pollsters they will buy only an American-made car — might reduce some of the patriotic associations with the activity of driving. Building a light-rail system might not persuade Bubba to get rid of his vehicle — but forcing him to buy foreign might.

I have a slightly different theory why this might be happening that I've touched on previously.  The oil shock didn't just affect consumer behavior.  It was also the pin that pricked the subprime bubble.  At it's peak, subprime loans accounted for around 20% of the mortgage market.  With those buyers disappearing, development into the transit-poor exurbs plummeted.  People either had to forgo buying their dream home and continue to rent, or purchase small single family and even multifamily homes, all markets which are found more readily in urban areas.

In this scenario, rather than making a conscious decision to living closer to work and services, people are being forced into this decision by market forces well beyond their control.  The unsustainability (spellcheck says this isn't a word but I'm going with it... it's Friday) of exurban growth patterns finally became too much for the market to bear and returned to the more stable model of growth focused in transit/pedestrian friendly urban areas.