Lester Brown of the Earth Policy Institute has a new report out today showing that the U.S. auto fleet shrunk by four million cars in 2009—the first time that's happened since World War II. All told, 14 million vehicles were scrapped and just 10 million were bought (by comparison, auto sales had been averaging about 17 million per year before 2007). Now, this could just be the recession talking, but Brown thinks it marks the beginning of a "cultural shift away from cars":

Among the trends that are keeping sales well below the annual figure of 15–17 million that prevailed from 1994 through 2007 are market saturation, ongoing urbanization, economic uncertainty, oil insecurity, rising gasoline prices, frustration with traffic congestion, mounting concerns about climate change, and a declining interest in cars among young people.

Market saturation may be the dominant contributor to the peaking of the U.S. fleet. The United States now has 246 million registered motor vehicles and 209 million licensed drivers—nearly 5 vehicles for every 4 drivers. When is enough enough?

Market saturation isn't unheard of: Japan, for one, hit "peak car" back in 1990, and sales have been dropping every year since. (Of course, Japan was struggling through economic stagnation all through the '90s, as well.) But there's other evidence that a shift is afoot. U.S. public-transit ridership has been climbing steadily since 2005, as cities like Phoenix and D.C. expand their networks. (Although D.C.'s about to backslide in a big way.) Local governments are rethinking their old habit of subsidizing free parking. People are worried that $4/gallon gas could come back. And, oddest of all, young people aren't nearly as excited about driving as they used to be:

Perhaps the most fundamental social trend affecting the future of the automobile is the declining interest in cars among young people. For those who grew up a half-century ago in a country that was still heavily rural, getting a driver’s license and a car or a pickup was a rite of passage. Getting other teenagers into a car and driving around was a popular pastime.

In contrast, many of today’s young people living in a more urban society learn to live without cars. They socialize on the Internet and on smart phones, not in cars. Many do not even bother to get a driver’s license. This helps explain why, despite the largest U.S. teenage population ever, the number of teenagers with licenses, which peaked at 12 million in 1978, is now under 10 million.

Really? Kids spend so much time on Facebook that there's no need to putter around in a car? I suppose it's plausible. We'll have to see if this trend continues once (if?) the U.S. economy starts growing again. It's not exactly good news for automakers—and makes you wonder how much longer Western governments can keep propping up an industry that may have to start shrinking. Although the other thing to note here is that even if Americans are buying fewer cars, developing countries are making up for it. China officially became the world's largest auto market last year, and by some estimates, the number of vehicles worldwide will double—to two billion—by 2020.

(Flickr photo credit: forwardlookguy)