(CNN) -- The average price for a gallon of regular U.S. gasoline slipped almost 7 cents over the past two weeks, chasing a drop in crude oil prices, according to a nationwide survey published Sunday.
A gallon of regular now costs $3.85 on average, the Lundberg Survey found. In the past month, average prices have fallen more than 12 cents.
"The price decline comes from lower crude oil prices," said publisher Trilby Lundberg.
That's good news for consumers, but it comes from a negative place, she said.
"Oil prices themselves are down because the oil market sees economic weakness in Europe and the United States, which is a negative for oil demand," said Lundberg.
The survey tabulates prices every two weeks at thousands of gas stations nationwide.
The average price nationally one year ago was just shy of $4 -- some 15 cents under the current average, Lundberg said.
The city with the lowest average price per gallon was Tulsa, Oklahoma, at $3.40. The city with the highest average price was Chicago at $4.32.
Here are prices in some other cities:
-- Atlanta: $3.68
-- Boston: $3.90
-- Denver: $3.82
-- Houston: $3.74
-- San Francisco: $4.21