Rising gasoline prices are likely to make business and leisure travelers alter their travel plans this summer, a survey to be released, Tuesday, by the U.S. Travel Association finds.More than half, 54%, of leisure travelers who planned to travel by car say higher fuel prices would affect their plans. A smaller percentage, 26.8%, of business travelers would reconsider their plans.It would take an increase of at least 26 cents to $1.25 a gallon for travelers to alter their behavior. According to the survey of 2,500 adults conducted March 8-11, 57% would change their plans if prices rose that much.The nationwide average for a gallon of regular gasoline was $3.90 on Monday, according to AAA. That's up 6 cents from a week ago and 32 cents from a year ago.Leisure travelers who planned on driving were more likely to cancel their trips because of higher gas prices. Almost half, 44%, say they'd take fewer trips this summer. If they did end up hitting the road, higher gas prices would fuel cutbacks, with 43.9% saying they'd shop less and 37.4% spending less on restaurants. More than a third say they'd drive shorter distances.Only about one-fifth of business travelers planning to drive would take fewer trips because of higher fuel costs. But they, too, would change their behavior on the road: 27.7% say they'd spend less at restaurants, 22.3% would spend less on lodging, and 19.8% would spend less on shopping."When travelers go to destinations, their positive impact in that area, that city, that state isn't just the fact that they're there, but that they're spending money," says David Huether, senior vice president of research for U.S. Travel. "The destinations and places where vacationers are going to be traveling to this year are going to see less economic activity."Roger Dow, the association's president, says the travel industry will respond by offering incentives such as gas cards and multiple-night deals at hotels. "The industry is going to be very proactive," he says. "We've been there before. We'll certainly weather this thing, but it bodes well for consumers to be able to find deals and extra value."Higher airfares, also being driven by higher oil prices, would affect leisure travelers more than business travelers, the survey found. Among leisure travelers who plan to fly, 43% would alter their plans if airfares increased, compared with one-quarter of business travelers.Leisure travelers would respond by seeking out a cheaper airfare (39%), flying less (27.4%) or spending less money on entertainment (27.2%). Another 10% would ditch plans to fly and find another way to travel.Business travelers would employ similar tactics to offset higher airfares, but not to the same extent. About one-third would search for a cheaper airfare, 22% would spend less on entertainment, and 20.2% would fly less. And 6% would switch to other modes of transportation.Still, Dow says, business travelers will have to become more efficient with their travel by planning ahead, shortening their trips or filling their schedules with as many appointments as possible on the road. "The business traveler has been under a tremendous amount of pressure with the economy already," he says.