GAITHERSBURG, Md. - Gasoline prices are once again inching up, spiking 19 cents per gallon over the past four weeks to reach an average of $3.48 per gallon for regular unleaded gasoline, the Chicago Sun Times reports. Experts predict prices could jump another 60 cents by May.

"I think it??s going to be a chaotic spring, with huge price increases in some places," said Tom Kloza of the Oil Price Information Service. Kloza forecasted nationally, pump prices will top $4.05 per gallon on average, with specific areas of the country experiencing higher prices.

"You could see prices in Chicago, Los Angeles, New York, Washington and other major metropolitan areas at $4.60 or higher," said Patrick DeHaan, an energy analyst with Gasbuddy.com.

While the spring generally brings an increase in pump prices given more demand and refineries switching to summer blends, 2012 has seen an earlier bump in prices more attributable to current supplies and demand. Other contributors include renewed Middle East tensions, oil speculators and temporary or permanent closures of some overseas and U.S. refineries.

"Higher demand, Iran, lost refining capacity are all potential problems. ?? We??ll get over $4 a gallon, but it??s going to be tough to sustain that level. People will drive less," said Brian Milne with Televent DTN.

For more on gas prices and consumer perceptions at the pump, check out the resources included in this year??s NACS Retail Fuels Report.