Fewer Americans plan to launch their summer season behind the wheel of an automobile this year, but a bump in air travel plans suggests that, overall, more people intend to get away from home this summer.

The high price of gas will deter some people from driving over Memorial Day weekend, the traditional kickoff of summer in the United States, according to a national survey by AAA.

With the price of gas $1.06 higher than it was a year ago — at $3.91 a gallon nationwide — the number of people who told AAA they would drive more than 50 miles from home slipped by 100,000 to 30.9 million.

Forty percent of would-be travelers said that gas prices would have an impact on their vacation planning, although nine out of 10 who said they would be traveling planned to do so by car.

A minuscule uptick in the overall number of people who are making Memorial Day weekend travel plans was attributed to increases in air travel.

Last year, a 14 percent overall jump in the number of travelers was seen as an indication that the country was emerging from recession.

“This year, we expect to add slightly to that gain due to an increase in air travel and an improvement in the overall domestic economic picture,” said AAA President Robert L. Darbelnet.

As the airlines try to rebound from a dreadful profit year in 2010, there are worries that fuel costs could drive up ticket prices.

In the first quarter of this year, U.S. airlines paid $11.4 billion for fuel, up 30 percent from the same period in 2010, according to the Air Transport Association of America, an industry trade group. The price of jet fuel is now at its highest level since the third quarter of 2008.

“Even as demand for air travel continues to improve, high and volatile energy prices could hamper recovery efforts,” said ATA President Nicholas E. Calio.

Despite worries about the cost of jet fuel, the airline industry has sounded optimistic about the prospects that an economic resurgence will encourage people to fly. The ATA estimates that an average of 2.24 million people will fly per day during the summer months.

That’s an increase of 34,000 per day when compared with last year, adding up to about 3 million more passengers from June through August.

The ATA says projected passenger numbers have not recovered from their pre-recession levels of summer 2008 and are well below the all-time high of 217.6 million passengers, set in summer 2007.

“It is encouraging that more people will be flying this summer, despite higher energy prices taxing the entire economy,” Calio said. “The trends are pointing in the right direction.”

The ATA says there has been little or no change in average airfares since 2000. In 2010, the average round-trip U.S. domestic airfare was $316. The average round-trip fare in 2000 was $314.

Although the number of passengers will be below the 2007 record, the ATA expects this will be a record-breaking summer for Americans taking international trips.

Of the 206.2 million passengers expected to travel on U.S. airlines this summer, 26.3 million will be traveling on international flights. That will surpass the record of 25.8 million international passengers set last summer.

Domestically, about 180 million passengers are expected to fly this summer, up from the 177.3 million who flew last summer. The record was set in 2007, when 192.4 million passengers flew domestically in the summer months.