Wednesday, June 1, 2011

Peak VMT?

The Melbourne Urbanist has a pretty great graphic:

The post discusses 'peak travel', the idea that the industrialized world has hit a peak, and gross Vehicle Miles Traveled  (VMT) will never be as high as they were in mid-2007. Gas prices are frequently mooted as the cause, which seems plausible.

But what struck me was less then decline in per capita miles traveled then the decline in Per Capita GPD. Historically, there has been a strong correlation between vehicle miles driven and economic growth, but the exact causal relationship has always been fuzzy--do richer countries drive more, or is more driving required for greater economic activity? (The latter is a favorite argument of the road lobby).

But gas prices are high, additional credit constrained, and American consumers are broke. I theorize that the price of gas has disrupted the American economic engine in unanticipated ways. It's not just businesses that are suffering from high gas prices, but employees. The Journey to Work is typically the farthest Americans travel in a week, and thus the one that uses the most gas. When gas was cheap, it made sense to live far from your job, where housing was cheap. The time-cost was high, but time is cheaper than gas.

With the housing market frozen, moving is much more difficult, so 'home' is fixed, and workers have to choose from jobs that are close enough that they can afford to drive there. And thus we have lingering long-term employment.