Sales of refined petroleum products in June fell 3.4 per cent in year-over-year comparisons, according to Statistics Canada. (CBC)

As summer vacation season kicked in, Americans got out of their cars, driving 19.6 billion fewer kilometres in June than the same month a year earlier.

The 4.7 per cent decline, which came while gas prices were peaking, was the biggest monthly driving drop in a downward trend that began in November, the Federal Highway Administration said Wednesday.

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

Overall, Americans drove 85.6 billion fewer kilometres 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 79.3 billion fewer kilometres driven by Americans over the entire decade of the 1970s, a period marked by oil embargoes and gas station lineups, the agency said.

Statistics Canada on Friday reported a 3.4 per cent year-over-year decline in sales of refined petroleum products in June, owing to weaker demand for gasoline and diesel fuel.

Travel Industry Association spokeswoman Cathy Keefe said the June driving decline "is not surprising, given the environment that we were in."

"I think people have started to take the increase in gas prices somewhat more in stride," Keefe said.

The U.S. trade association is predicting only a 1.2 per cent decline in all forms of business and leisure travel this year.

Travel to Maine, Florida, Montana falls

Some of the biggest declines in June compared with a year ago were in such popular vacation states as Maine, down 7.0 per cent, and Florida, down 6.0 per cent. Western states with wide-open spaces were also part of the trend — down 7.7 per cent in Montana, 6.9 per cent in Washington, 6.8 per cent in Wyoming, 6.7 per cent in Nevada, 6.2 per cent in Kansas and 6.1 per cent in Alaska.

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

Four in 10 said they have used public transportation, walked or ridden a bicycle more frequently since gas prices have risen, according to the AARP poll, which was being released Wednesday.