Happy Motoring in the U.S. has peaked

My regular readers will recognize the miles driven graphs I include with my driving updates, the last one of which I posted in April, along with another adjusted for population.  The latter one always reminds me of something.

I've posted earlier versions of this graph twice before.  Both times I remarked about how it mimicked the classic Peak Oil graph, right down to the expected timing, and asked "Peak Driving, anyone?"  The resemblance has, if anything, become more striking.

It turns out that it isn't just the miles driven that reflects the classic Peak Oil graph, it's the number of cars on the road that does, too, as the following Univeristy of Michigan press release asks, Has motorization in the US reached its peak?

Fewer light vehicles are on America's roads today than five years ago, thanks possibly to increases in telecommuting and public transportation, says a University of Michigan researcher.

Michael Sivak, a research professor at the U-M Transportation Research Institute, studied recent trends in the numbers of registered cars, pickup trucks, SUVs and vans in the U.S. from 1984 to 2011. He examined both the absolute numbers and rates per person, per licensed driver and per household.

Sivak found that the absolute number of registered vehicles reached a maximum of 236.4 million in 2008, 2.6 million more than in 2011.

"It is likely that this was only a temporary maximum and that the decline after 2008 was primarily driven by the current economic downturn that started that year," Sivak said. "Consequently, with the improving economy and the expected increase in the U.S. population, it is highly likely that from a long-term perspective, the absolute number of vehicles has not yet peaked."

The press release doesn't include either a graph of total cars or a link to one, but the figures mimic those of the total miles driven graphs, the latest of which from Doug Short is below.



 The resemblance continutes, as does the press release.

He found, however, that rates of vehicles per person, per licensed driver and per household reached their highest levels most recently in 2006—two years before the economy stalled. The rates that year were 0.79 vehicles per person, 1.16 per licensed driver and 2.05 per household. In 2011, the rates were 0.75, 1.10 and 1.95, respectively.

Normalize miles driven by the population, and it shows that same relationship.



Peak driving and peak cars, anyone?

Sivak has more about what this means.

"It is likely that the declines in these rates prior to the current economic downturn reflect other societal changes that influence the need for vehicles—such as increases in telecommuting and in the use of public transportation," Sivak said.

Sivak said that changes in the rates from 2008 on, however, likely reflect both the economy and a variety of societal changes.

"Whether the recent maxima in the rates will represent long-term peaks, as well, will be influenced by the extent to which the relevant societal changes turn out to be permanent," he said.

In the meantime, transportation decisions are still being based on the old way of doing things, but they need to change.

"The Driving Boom is over," said Phineas Baxandall, Senior Analyst at the U.S. PIRG Education Fund and co-author of the report. "The constant increases we saw in driving up until 2005 show no sign of returning. As more and more Millennials become adults, and their tendency to drive less becomes the norm, the reduction in driving will be even larger."
...
"Given the magnitude of these trends and the implications for the future, we need to press the reset button on our transportation policy,” said Baxandall. "Public officials can’t just stay on the only course they’ve known. They need to learn from current trends to rethink whether it's worth building all those extra highway miles that were planned based on an obsolete understanding of future driving trends."

So long, Happy Motoring!