WASHINGTON – The summer vacation season began this year with Americans behind the wheel less. In all, we drove 12.2 billion fewer miles in June than a year earlier, the biggest monthly decrease in a downward trend that began in November.

That decrease, reported by the Federal Highway Administration, coincided with the national average price for unleaded gasoline hitting $4 a gallon for the first time on June 8. It peaked in mid-July at $4.11 and was down to $3.78 on Wednesday, according to AAA.

“Clearly, more Americans chose to stay close to home in June than in previous years,” Transportation Secretary Mary Peters said Wednesday.

Overall, Americans drove 53.2 billion fewer miles from November through June than they did over the same eight-month period a year earlier, according to the highway agency’s latest monthly report on driving. That’s a larger decline than the 49.3 billion fewer miles driven by Americans over the entire decade of the 1970s, a period marked by oil embargoes and gas lines, the agency said.

Travel Industry Association spokeswoman Cathy Keefe said the June driving decline “is not surprising, given the environment that we were in.” But she predicted the recent drop in gas prices to below $4 a gallon in many parts of the country will have travelers on the road again.

“I think people have started to take the increase in gas prices somewhat more in stride,” Keefe said. The trade association is anticipating only a 1.2 percent decline in all forms of business and leisure travel this year.

Some of the biggest declines in June, compared with a year ago, were in such popular vacation states as Maine, down 7 percent, and Florida, down 6 percent. Western states with wide-open spaces were also part of the trend – down 7.7 percent in Idaho, 6.9 percent in Utah, 6.8 percent in Washington, 6.7 percent in Nevada, 6.2 percent in Kansas and 6.1 percent in Alaska.

The June driving data, collected by more than 4,000 automatic traffic recorders operated around-the-clock by state highway agencies, were supported by an AARP telephone survey of people age 50 and over in which 67 percent said they have cut back on their driving because of high gas prices.