Pennsylvania drivers are enjoying slightly lower gas prices. As reported by Triple-A, the average price for a gallon of regular fell Friday in the Keystone State to three dollars and 71 cents, as the national average also sank slightly to three-56 a gallon. Prices remains lowest in Mississippi, where the statewide average fell slightly on Friday to just over three-04 a gallon. Meanwhile, prices were still highest in California, with yesterday’s Golden State average dipping slightly to just under four-84 a gallon.