Raleigh, N.C. — Gasoline prices are on the rise again.

Average retail prices in Raleigh have risen 7.9 cents per gallon in the past week, averaging $3.38 per gallon as of Sunday, according to the gasoline price website RaleighGasPrices.com.

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Nationally, the average that has increased 4.9 cents per gallon in the last week, to $3.48 cents per gallon.

Part of the reason, North Carolina State University economist and professor Mike Walden says, is that drivers drove a little more when prices were lower.

"You're always going to have a rebound from that," he said Monday. "The price will go back up a little bit as people drive more."

But there are several other factors at play, Walden says, including increased tension in the Middle East and the increased cost of ethanol because of a drought in the Midwest, which is affecting the price of corn.

"You can't really figure it out, because it is based on factors largely beyond the control of individual drivers," he said.

Walden says, however, that he doesn't expect the prices to rise to the $4 mark.

Drivers say they're looking for consistency, but that there's not much they can do.

"You just got to deal with it," driver Jordan Kirk said. "I don't know what to do about it."