LYNN – Prices for a gallon of regular unleaded gasoline are soaring beyond $3 across the country as the Thanksgiving holiday approaches.The Massachusetts average on Monday was $2.92, up from $2.88 last week and a full five cents above the national average, according to Mary Maguire, director of public and government affairs for the American Automobile Association (AAA).”Our survey found that gas prices increased four cents in the past week and 10 cents in the past two weeks,” said Maguire, noting that a gallon of regular unleaded averaged $2.61 a year ago.The survey included 22 service stations in southern New England.”When we look at the range, we see an increase of 30 cents, from a low of $2.79 to a high of $3.09. But having lived through the summer of 2008 when gas prices topped $4 a gallon, I wouldn’t call this a spike. I would call it gradually creeping up,” Maguire said.In Lynn, the pump price of gasoline at Arctic Oil on Washington Street fluctuated with the market. According to Scott Finlay, fuel buyer at Arctic, unleaded regular sold for $2.95 over the weekend and was back down to $2.89 on Monday, three cents lower than the state average.Prices at service stations along the Lynnway on Monday were all higher than the state average. The Shell station prices ranged from $2.99 for regular unleaded to $3.21 for premium. The Mobil station pumps offered a similar range, from $2.97 to $3.21, while Spiro’s prices were $2.97 to $3.18.Oil prices are partly to blame, reaching $88 per barrel a couple of weeks ago and maintaining that level on Monday. “Oil has seen very little movement but we are heading into a period of heavy demand when 42.2 million people will travel up to 50 miles from their homes on Thanksgiving Day. Ninety-four percent of those people will go by car, the highest percentage of drivers we have ever projected for a major holiday.”Despite the price increases at the pump, Americans seem willing to stay on the road.”People are not terribly discouraged because they have already made their holiday travel plans,” Maguire said.Although some gasoline retailers may be tempted to gouge consumers during the holiday weekend, the best defense is to avoid gas pumps where prices are well above the average.”If you know the magic number, then you are a smart consumer. You need to be looking in the low $2.80s for regular unleaded,” Maguire said.The Nov. 22 AAA survey found one self-serve station selling premium for $3.45, she said.”It pays to shop around,” Maguire said.