Gas prices have jumped, ending a downward slide, according to a survey published Sunday.

The average price of a gallon of self-serve regular gasoline is $3.47, up five cents over the past two weeks, the Lundberg Survey found.

From early September to early October, the price had dropped 25 cents.

The new spike follows a moderate rise in crude oil prices, as well as a dramatic increase in the cost of ethanol, said publisher Trilby Lundberg.

“This doesn’t portend that we will see much bigger increases from here,” she said. “Crude oil will decide that. If crude oil prices don’t jump up in any extreme, then I doubt price changes will be significant in either direction.”

Low demand is helping drag prices down, she said, citing unemployment and underemployment.

The price is 64 cents higher than it was a year ago.

The Lundberg Survey tallies prices at thousands of gas stations nationwide.

The city with the lowest average price in the latest survey was Albuquerque, New Mexico, at $3.15. The highest was Los Angeles, at $3.86.

Here are average prices in some other cities:

• Boston – $3.55
• Atlanta – $3.45
• Chicago – $3.55
• Denver – $3.47
• Tulsa, Oklahoma $3.30
• Seattle – $3.81