BOSTON – Vacationers going away for the upcoming Fourth of July weekend may find the roads somewhat less congested than they did last year, according to AAA Southern New England.

The auto club said today it expects 37.1 million Americans to travel 50 or more miles from home for the Fourth, which falls on a Saturday this year. That would be down 1.9 percent compared with 2008.

Among those who travel, 88 percent are expected to go by car, although the number of automobile trips are projected to decline 2.6 percent compared with last year. The number of air travelers, on the other hand, is expected to increase by 4.9 percent to 2 million due “to declining airfares and pent up demand from those who have not taken a vacation trip by air in some time,” AAA said.

In New England, 17 percent of the population will travel 50 or more miles for the Fourth, fewer than last year but still the highest percentage of any region, AAA said. The average trip distance will be 414 miles roundtrip for New Englanders, compared with 614 miles nationwide.

AAA said fewer people are planning to go away because of continued concerns about the strength of the economy. Higher gas prices may also play a role, although the auto club said “its impact on overall vacation costs remains minimal.” The average price of self-serve, unleaded regular at stations in Rhode Island was $2.70 per gallon on Monday, according to AAA.

“Many Americans remain cautious about the outlook for their personal finances and these attitudes are reflected in the slight decline in travel we are forecasting for the upcoming holiday weekend,” Lloyd P. Albert, AAA Southern New England’s senior vice president of public and government affairs, said in a statement.

But Albert also noted a silver lining for some travelers in the down economy – better deals from hoteliers, travel agents and other businesses competing more fiercely than usual.

“Those who do vacation this summer will find attractive discounts and special offers resulting in some outstanding vacation values,” he said. “If you can afford to go, this summer is a smart time to travel.”

AAA projects the average New England household that travels for the Fourth will spend $822 on its trip, far below the national average of $1,160 per family.

Transportation and accommodations will account for roughly half the average cost of a trip, with food and beverage taking another 20 percent and shopping, entertainment and recreation accounting for the rest.

“The July Fourth holiday is typically the busiest time of year for auto travel since nearly all school-aged children are out of school at this time and, as a result, parents are more apt to take family vacations,” AAA said.