Pennsylvania motorists are faced with slightly higher gas prices this week. As reported by Triple-A, the average price for a gallon of regular rose slightly on Friday in the Keystone State to three dollars-81 cents, this as the corresponding national figure dipped to just under three-sixty-seven. Prices continue to be lowest in Mississippi, rising incrementally to a few tenths over three-twelve on Friday. At the opposite end of the gas-price spectrum, California’s average price at the pump declined to just under five-thirty-seven per gallon.