By Tim Molloy
The Associated Press

LOS ANGELES - Gas prices across the country climbed another 3 cents in the past two weeks to an average of $1.80 for all grades, setting a new record high, according to a study released Sunday.

There is little chance of prices falling significantly in the near future, because increased demand will likely result from an improving economy, Memorial Day travel, and even the extra hour of light from daylight savings time, said Trilby Lundberg of the Lundberg survey, which covers 8,000 stations nationwide.

"The demand push this time of year is adding to supply tightness and therefore price," Lundberg said.

San Diego has the highest gas prices in the country, at $2.12 for a gallon of regular unleaded. Los Angeles is close behind, at $2.10 for a gallon of regular unleaded.

Even if the Organization of Petroleum Exporting Countries decides at its meeting Wednesday to cancel plans to reduce oil production April 1, growing demand makes it unlikely prices will fall much, Lundberg said.

An improving U.S. economy may be a bad sign for gas prices because it means increased transportation demands, Lundberg said.

Gasoline prices are up 29 cents per gallon nationwide since late December, Lundberg said. The national weighted average price of gasoline, including taxes, at self-serve pumps Friday was about $1.77 for regular, $1.87 for midgrade, and $1.96 for premium.

Gasoline prices usually rise between March and May as refiners temporarily shut down their plants to prepare for the peak summer driving season, when special clean-burning blends of fuel are required. These shutdowns shrink supplies.

This year, the effect on price has been magnified because commercial gasoline inventories are already low. For the week that ended March 12, U.S. inventories stood at 199.6 million barrels, down from 202.1 million barrels a year ago.

Adjusted for inflation, the current price fell short of the record set in March 1981, when prices were about one-third higher in today's dollars, Lundberg said. The March 1981 combined average for all grades was about $1.38, the equivalent of $2.85 in today's dollars.

Last week, an Energy Department study showed a jump to $1.743 in the national average for regular grade gasoline in the week ended March 22, up from $1.724 the week before. That's still 0.4 cent below the record the agency reported last August.

The Lundberg study is different in part because it measures the combined average of all grades, not the average price of regular grade.