American motorists are bracing for further increases in gas pump prices this summer after average national prices rose 12 cents in the past week alone. AAA says drivers are experiencing “sticker shock” as increased summer demand, unrest in Egypt and production disruptions in the U.S. and other countries push up the price of crude oil and gasoline. The national average price for regular unleaded gasoline was $3.67 a gallon on Friday. AAA says that’s 23 cents more expensive than the same time last year but still below the all-time daily high of $4.11 a gallon on July 17, 2008. The association says retail gas prices are likely to rise more in the coming weeks. Unscheduled refinery shutdowns or hurricanes on the U.S. Gulf Coast could also add to price increases.