HOUSTON ─ As the national average cost for a gallon of gas hovers just below the $3-a-gallon level, market research company The NPD Group wonders whether consumers will alter their holiday travel plans as a result. Historically, $3 a gallon for gas has been the tipping point at which consumers adjust driving behaviors, NPD says.

According to a holiday survey conducted this past September by The NPD Group, 63 percent said that they would not be changing their holiday travel plans in light of gas prices. The survey also found that fewer people would be staying home this year than last year when 30 percent of respondents said they planned to stay home, versus 27 percent who said they would be staying home this year.

“After surviving $4-a-gallon gasoline in 2008, consumers have gradually begun to return to normal driving behaviors, but any sustained price increase over $3 a gallon would likely cause these numbers to start trending back in the other direction,” says David Portalatin, a motor fuels analyst with The NPD Group. “Sustained gas price increases over the next month could cause some to reconsider winter holiday driving travel.”

NPD’s motor fuels market research, which continually tracks consumer motor fuel purchasing behaviors and attitudes, finds that at the $3 a gallon mark consumers begin making short-term adjustments to their driving behaviors by driving less, idling less, driving slower and carpooling. Since gas prices have been below $3 a gallon, consumers are gradually reversing their short-term driving adjustments. For example, in 2008, 60 percent of consumers said they were driving less, while 33 percent said they were driving less in 2010.

“We may expect to see these types of driving adjustments at the holidays if gas reaches $3 a gallon by mid-December,” said Portalatin. “But if holiday plans have already been made by that time, consumers will more than likely stick with their plans.”