If you haven’t filled up lately, get ready for a little sticker shock. Gas prices are spiking.

We’ve seen it as high as 3.85 a gallon for regular gas at stations in the area.

So what's driving up prices?  We are just two weeks away from the deadlines for refineries to start producing a new summer blend of fuel. AAA spokesperson Mark Jenkins said that’s leading to declining supply. Couple that with increased demand and you’ve got higher prices.

AAA has the average price at $3.70, nine cents higher than it was a week ago.That's 30 cents higher than this time last year.

“I expect by the end of the year it will be up to $4 a gallon,” Ricky Otteson said while filling up.

AAA had predicted gas prices will peak this month at no higher than than a national average of $3.75 a gallon. But Jenkins said geopolitical international concerns in Russia and the Ukraine could drive up crude oil prices.

General Contractor George Ruiz spent $200 filling up generators and trucks Thursday.

“No matter how much we argue it, we've still got to pay it, so why argue it it’s something we need everyday,” he said.

We are still below last year’s peak average price of $3.88 a gallon. That happened in February and everyone was sure we’d hit $4, but most gas stations never did.