The average U.S. price of regular-grade gasoline surged 13 cents a gallon over the past two weeks, to $2.91.Industry analyst Trilby Lundberg, of the Lundberg Survey, says one of the reasons for the spike is an increase in crude oil costs.Lundberg says Sunday that prices at the pump have jumped 25 cents over the past month and 60 cents over the past 14 weeks.The highest average price in the nation is $4.04 a gallon in the San Francisco Bay Area.The lowest average is $2.45 in Baton Rouge, Louisiana.The average price of diesel rose 4 cents over the past two weeks, to $3.14.