Gasoline prices began leveling off throughout much of the Southwest last week following price spikes caused by production interruptions at three Northern California refineries, according to the Automobile Club of Southern California's Weekend Gas Watch. Gasoline production has returned to normal, easing fears that there would be a supply shortage. Currently, the average price of self-serve regular unleaded gasoline in the Los Angeles-Long Beach area is $1.774 per gallon, which is four-tenths of a cent lower than last week's price, 3 cents lower than last month and 14 cents higher than last year. In San Diego, the price is $1.781, which is 1.5 cents above last week's level, 1 cent above last month and 13 cents above last year. Motorists in the Central Coast have an average price of $1.894, which is six-tenths of a cent lower than last week's price, 4 cents lower than last month and 19 cents higher than last year. "Wholesale prices are stable and there is ample supply to meet motorists' demand," said Carol Thorp, spokesperson for the Automobile Club of Southern California. "Barring any unforeseen circumstances, we should see prices remain at this level or even edge slightly lower through the July 4 holiday period."