As Americans’ reliance on cars has declined in recent years, it’s been easy to argue (and many have) that that shift was due to the economic recession rather than some intrinsic change in the nation’s psyche. Now, results from a new study released by the University of Michigan indicate that the U.S. began shying away from driving in 2004, well before the recession kicked in. Quartz reports:

The year 2004 was the US peak for absolute distances driven, and for miles traveled per licensed driver, per household and per registered vehicle. Absolute miles driven in US-registered light vehicles declined by 5% from 2006 through 2011, to 2.6 trillion miles from 2.7 trillion miles. The distance per licensed driver fell to 12,492 miles in 2011 from 13,711 in 2004, an 8.9% decline. Households as a whole were driving 9.4% fewer miles in 2011 as compared with 2004.

Here’s a graph of those data, from the U of M study:

And here’s the study author, Michael Sivak, on the drivers behind his findings:

These reductions likely reflect, in part, noneconomic changes in society that influence the need for vehicles (e.g., increased telecommuting, increased use of public transportation, increased urbanization of the population, and changes in the age composition of drivers). Because the onset of the reductions in the driving rates was not the result of short-term, economic changes, the 2004 maxima in the distance-driven rates have a reasonable chance of being long-term peaks as well.

This is good news for both the country and the planet, since less driving means less dependence on fossil fuels and a reduction in greenhouse gas emissions.

More from Smithsonian.com:

The Origins of the Drive-In Theater

Fuel for Thought