“The average price of a gallon of regular gasoline has jumped 45 cents in the past 31 days, according to AAA, the fastest run-up since 2005. Retail gasoline prices have climbed for 33 days in a row. A month ago, a gallon of regular gasoline cost $3.30; on Tuesday it stood at $3.75 nationwide. Gasoline prices have risen to within a nickel of $4 a gallon in the District as pump prices nationwide have been marching higher — the result of refinery closures and maintenance, lower oil production by Saudi Arabia, market anxiety about tensions in Iran and Iraq, and guarded optimism about the prospects for economic recovery in the United States, Europe and China. The prices in the District are among the highest in the country, outstripped only by New York, Connecticut, California and Hawaii. “This is the most expensive we’ve seen gasoline in the dead of winter,” which is ususally a time of relatively low consumption, said John Townsend, a spokesman for AAA Mid-Atlantic. Noting that the increase comes just as the payroll tax cut has expired, Townsend said that “this is a double whammy for many consumers, especially on the East Coast, because many people there use home heating oil. . . . People got that shock to the system and now a shock at the gas pumps.” The price increases have been a rude reminder that even though the United States’ reliance on imported oil is less than it has been in nearly two decades, prices at service stations are still tied to global prices and subject to global market trends, as well as to regional refinery constraints.”