Trends indicate that Norrington, who works in marketing for the nonprofit American Legacy Foundation, is one of many Americans who have recently decided to use their cars less, sell them or not buy one in the first place. Whether motivated by convenience, cost or other phenomena, Americans are driving less and traffic is easing up, a growing number of studies show.

According to the Federal Highway Administration’s “2011 Urban Congestion Trends” report, there was a 1.2 percent decline in vehicle miles traveled (VMT) last year compared with 2010. The drop follows years of stagnant growth in vehicle travel following a peak in 2007, before the economic downturn.

“Traffic really is as much a reflection of a given urban environment as it is the health of our economy,” said Jim Bak, director of community relations at the transportation research firm INRIX, which found that traffic congestion in the United States fell by 27 percent last year.