PRESIDENT OBAMA’S ambitious goals to curb the United States’ greenhouse gas emissions, unveiled last week, will get a fortuitous assist from an incipient shift in American behavior: recent studies suggest that Americans are buying fewer cars, driving less and getting fewer licenses as each year goes by.

That has left researchers pondering a fundamental question: Has America passed peak driving?

The United States, with its broad expanses and suburban ideals, had long been one of the world’s prime car cultures. It is the birthplace of the Model T; the home of Detroit; the place where Wilson Pickett immortalized “Mustang Sally” and the Beach Boys, “Little Deuce Coupe.”

But America’s love affair with its vehicles seems to be cooling. When adjusted for population growth, the number of miles driven in the United States peaked in 2005 and dropped steadily thereafter, according to an analysis by Doug Short of Advisor Perspectives, an investment research company. As of April 2013, the number of miles driven per person was nearly 9 percent below the peak and equal to where the country was in January 1995. Part of the explanation certainly lies in the recession, because cash-strapped Americans could not afford new cars, and the unemployed weren’t going to work anyway. But by many measures the decrease in driving preceded the downturn and appears to be persisting now that recovery is under way. The next few years will be telling.

“What most intrigues me is that rates of car ownership per household and per person started to come down two to three years before the downturn,” said Michael Sivak, who studies the trend and who is a research professor at the University of Michigan’s Transportation Research Institute. “I think that means something more fundamental is going on.”