Self-serve regular averaged about $2.94 a gallon, up from $2.91 two weeks ago, said Trilby Lundberg, who publishes the nationwide Lundberg Survey of roughly 7,000 gas stations.
The average price of mid-grade was $3.04 a gallon, up from $3. Premium hit $3.14 a gallon, compared with $3.10 two weeks ago.
The survey covered the period from April 21 through May 5.
Of the stations surveyed, the highest average price in the nation for regular unleaded was found in San Diego at $3.41 a gallon. The lowest was in Cheyenne, Wyo., where drivers paid an average of $2.61 a gallon.
Among the California cities surveyed, Stockton had the lowest average price for regular unleaded at $3.19.
An Associated Press poll found that continuously rising gas prices is taking its toll on Americans' lives.
Seven in 10 said gas prices are causing a financial pinch. Two-thirds of people said they have cut back on driving and have reduced the use of heating and air conditioning. Half now say they have trimmed their vacation plans.
When asked what would be a fair price for gasoline, many of those surveyed said $2-a-gallon on average — a price not seen consistently in the U.S. for more than a year.
The number of people who say gas prices are causing them money problems has risen from half to two-thirds in the last year, the poll found.