Gasoline prices have surged upward an average of 20 cents per gallon in the last two weeks, raising fears among motorists prices could hit $3 per gallon again this summer.

"Oh God, I just hope not!" said Munster resident Maggie Nolan as she pumped gas into her compact car Tuesday morning at the BP gas station at the corner of Calumet Avenue and Main Street in Munster.

When gas prices started going up last month, the full-time Governors State University grad student took a second job and got a BP credit card that offers her a rebate on every gallon.

Gasoline prices had dropped dramatically in late summer and some stations offered regular at prices less than $2 per gallon for a brief period during the winter.

Prices are spiking upward unusually early this year, according to Beth Mosher, of the Chicago Motor Club of the American Automobile Association.

"We have seen in the last two weeks a rapid rise for this time of year," Mosher said. "We usually don't see that steep a rise until late spring or early summer."

Motorists nationally paid an average of $2.54 for a gallon of regular at the beginning of the week, a rise of 33 cents in the last month, according to the AAA Fuel Gauge Report. In Northwest Indiana, a gallon of regular now averages $2.47 per gallon, up 23 cents in the last month.

A combination of factors is fueling the increase, including high demand, oil prices above the $60 per barrel mark, and refineries shutting down some production to get ready for producing summer blends.

So far, experts do not expect gas to reach $3 per gallon gas this summer, at least in the Midwest, Mosher said.

Prices already have reached that summit on the West Coast, where a gallon of regular averaged $3.10 per gallon in the San Francisco area over the weekend.

The Organization of Petroleum Exporting Countries, which reduced oil output late last year and again in February, meets Thursday in Vienna, Austria. So far, cartel members are expressing confidence world oil demand remains robust, and they do not plan production cuts.

A Lundberg Survey released Sunday showed a gallon of regular has risen 20 cents in the last month alone, accelerating the price increases which began in January.

Consumers appear to be growing accustomed to gasoline in the $2 per gallon range. Many analysts say prices would have to break the $4 per gallon mark to significantly change buying or driving habits.

Filling up her Ford Expedition at the BP station after driving to Andrean High School early Tuesday morning, Cathy Kapischke said saving time usually trumps all in her book.

"I come someplace where it's convenient," she said. "If I see a low price, I might stop in -- if I have time."