Gasoline prices across the country rose more than 14 cents in the past two weeks and show no signs of slowing their climb, an industry analyst said on May 23, according to the Associated Press. The weighted national average for all three grades of gasoline was $2.10 per gallon on May 21, according to Trilby Lundberg, publisher of the biweekly Lundberg Survey, which regularly polls 8,000 gas stations across the United States. The rise was caused by increased demand created by market pressures and seasonal environmental regulations requiring a move to costlier formulas, she said. “So far the higher prices have not chased demand away, and our biggest demand season is yet to come,'' she told the Associated Press. “There is no evidence yet that gasoline prices are peaking. They may soon, but there's no evidence that that is occurring yet.'' The Organization of Petroleum Exporting Countries, which had decided in March to cut its official output, has come under growing pressure from the United States and other consuming nations to boost production as oil prices rose above $40 a barrel in recent weeks. But Lundberg said oil price drops won't necessarily result in lower U.S. gas prices. She said the reductions would be at least partially offset by increased demand from economic growth, environmental regulations, and an increase in driving during the summer months. The average price of gasoline has broken all-time record highs for three months straight, although the average price remains lower than the peak gas price in March 1981 when adjusted for inflation, Lundberg said. That price, adjusted for today's dollars, was $2.91 for all grades combined, she said. The national weighted average price of gasoline at self-serve pumps on Friday, including taxes, was about $2.07 for self-service regular; $2.17 for mid-grade, and $2.26 for premium. San Diego had the highest average price of any city, with self-serve regular selling for an average of $2.36. The average for self-serve regular in California was $2.33.