It is a well-established fact that Americans are driving less today than they were in 2004, the peak year for Vehicle Miles Traveled per capita. The lingering question is what accounts for the change: changing lifestyles and transportation preferences, a dismal economy or something else?
A new report by the USPIRG Education Fund concludes that the economy, as measured by the unemployment rate, has had only a tangential effect on driving. The study constructed a graph of the 50 states and Washington, D.C., comparing the change in employment and VMT per capita between 2005 and 2011 and found a weak correlation. The implication is that other factors must be responsible for the shift in behavior.
Only seven states increased VMT per capita over that six-year period, most only marginally so. Every other state, including D.C., saw declines. In some cases, the declines were remarkable. D.C., for instance, saw a decline of 21.7%. In Georgia, driving tumbled 16.6%. (Virginia was in the middle of the pack, showing a 7.0% decline per capita.)
“Among the 23 states where driving declined faster than the national average,” the report states, “only 11 saw faster-than-average declines in the employed share of their working-age population.”
The evidence suggests that the nation’s per capita decline in driving cannot be dismissed as a temporary side effect of the recession. While certainly a contributing factor and an economic rebound could be expected to have some upward lift on driving, the recession does not appear to be the prime cause of the fall off in driving over the past eight years. Nor is it clear that future economic growth would lead to a resumption of the postwar Driving Boom. Policy makers can stop wondering whether American driving trends are changing. They should focus carefully on these trends, and start adapting policies to match them.
While I am inclined to agree with the authors that the macro economy is a modest factor in explaining the dip in driving, I find this study less than conclusive. Employment/unemployment is only one measure of economic activity. Another vital measure is income. The USPIRG study found that people living in states with higher average household incomes drive less on average than people in states with lower incomes. But that may simply reflect the fact that people with higher incomes tend to live in more urbanized states, where they have greater access to mass transit, while people with lower incomes live in more rural states, where destinations are scattered over greater distances. The study did not compare the change in income with the change in in VMT. It is plausible to hypothesize that people who experienced a loss in income tended to drive less. Until someone runs that analysis, I don’t think we can state that the debate has been definitively settled.