NEW YORK (CNNMoney.com) - American drivers are being socked with skyrocketing gasoline prices and could even see shortages this summer as refineries struggle to switch additives that make cleaner burning fuel.

Nationwide, average gas prices shot up another cent and a half Monday to $2.676 for a gallon of regular, according to a survey by AAA. A year ago the average was $2.272.

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The jump adds to a trend seen over the last month or so.

Over the last two weeks gasoline prices have surged 17 cents per gallon, said Trilby Lundberg, publisher of the Lundberg Survey, which tallied prices March 24 and April 7 for its latest survey released Sunday.

Since Feb. 24, the average price of a gallon of self-serve unleaded has risen 42 cents, said Lundberg.

"Some of the pump price surge comes from higher crude-oil prices, but most is the new fuel specifications resulting from energy-bill provisions and EPA regulations," she told CNN.

Work to complete repair of damage to refineries caused by last year's hurricanes and the work needed to comply with the 2006 fuel requirements "is more costly and more complex than what is usually required," she said.

That work is taking some of the nation's refining capacity, and therefore its gasoline production, off line, she said.

The result could be spot gas shortages or price spikes, said Energy Secretary Samuel Bodman.

"We face a combination of factors that could mean some localized shortages," Bodman said in a recent interview with Reuters.

Like Lundberg, he placed much of the blame on refinery slowdowns or closures as they switch from the additive MTBE to ethanol.

Both are intended to make fuel cleaner burning, but the chemically derived MTBE is being phased out in favor of corn-derived ethanol. MTBE has been shown to be a powerful groundwater contaminant, fouling supplies when it leaks from underground storage tanks at gas stations.

Most ethanol is produced in the midwest, and Bodman said shortages could occur further from supplies.

"We expect there will be sufficient ethanol," Bodman reiterated. "But it is reasonable to expect that some areas could experience fits and starts, but that shouldn't last too long."

He also said another active hurricane season, which is predicted, could disrupt refining capability and add to price spikes.

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