Mainers planning trips this summer should be prepared to pay more at the pumps for gas this summer, as prices have jumped an average of 21 percent nationwide in the last year, with drivers in nine states already paying $3 a gallon for regular gasoline, according to The national average price of regular unleaded gasoline touched $2.83 a gallon on May 9, up 17 cents the past month and 49 cents the past year, reports USA Today. This sign shows the prices for gas at the Circle K/Big Stop on North Street in Houlton on Friday, May 11. Credit: Jen Lynds

U.S. drivers might be feeling flush after getting tax cuts amid a growing economy as they embark on the summer driving season, but road trips will cost more this year.

Drivers are already paying an average of $2.90 for a gallon of regular gasoline. There may be no relief in sight as oil in London topped $80 a barrel Thursday on tightening global supplies. The traditional Memorial Day holiday kickoff of summer driving season may test the strength of the economy and consumers’ desire to hit the road as temperatures rise.

Prices have risen for nine days straight, according to AAA. While average costs aren’t expected to approach the record $4.14 a gallon reached in July 2008, there’s a 75 percent chance they will soon reach $3, Patrick DeHaan, head of petroleum analyst at GasBuddy, said in a phone interview Thursday.

For the three months of summer, assuming prices don’t rise any more, Americans will pay an average $100 more for gasoline than a year earlier, DeHaan said.

“I think people may cut back on fast casual dining or McDonald’s on the way to the lake,” DeHaan said. “I don’t know that we will see a net drop in demand. While this may curb or slow down discretionary demand, it will be offset by the strength of the economy. And I think the worst-case scenario is $3.15 to $3.20.”

The higher prices aren’t expected to stop Americans from hitting the road. AAA projects a 4.7 percent jump in travel by automobile over the U.S. Memorial Day holiday weekend.

Retail gasoline prices “are going up,” Ashley Petersen, lead oil analyst at Stratas Advisors in New York, said in a phone interview. “Hopefully, you took your road trip last year because it is going to be more expensive this year.”