ATLANTA (CNN) - Gas prices rose an average of just over 3 cents a gallon in the last two weeks, continuing their record-breaking climb, the publisher of a national survey said Sunday.
The national average for a gallon of self-service, regular unleaded gasoline rose to $1.83, according to the Lundberg Survey of more than 7,000 U.S. filing stations taken April 23.
That's an increase of almost 35 cents a gallon since Dec. 19, when prices began rising.
Trilby Lundberg, who publishes the gas survey, said high consumer demand and a low supply cushion were driving up prices.
Higher crude oil prices fueled by OPEC production cuts, uncertainty over Iraq's oil production and strong world demand -- especially in the United States and China -- were part of the reason for the increase, she said.
The United States also has tight refinery capabilities and new environmental specifications for gasoline. Those specifications have made it more difficult to import gasoline into the United States.
Lundberg said demand was growing steadily, despite the record prices.
San Diego remains the most expensive place to buy gasoline, with a gallon of self-service regular unleaded now at $2.17 -- that's 5 cents less than two weeks earlier.
Tulsa, Okla., had the lowest price at $1.66 a gallon, but that's an increase of 7 cents since the last survey.
Gas prices in a sampling of cities: Portland, Ore. -- $2.01; Washington, D.C. -- $1.83; Cleveland -- $1.83; Boston -- $1.81; Denver -- $1.80; Albuquerque -- $1.73; Atlanta -- $1.68; Houston -- $1.67;