May 16, 2008 - Santa Rosa s average price for regular gasoline was 3.944 a gallon today, according to AAA. A year ago, it was 3.440.Among the area s typically low price stations, these prices were reported this morning 3.829 at Arco at Hearn and Corby avenues in Santa Rosa. 3.839 at Arco at Fourth Street and Brookwood Avenue in Santa Rosa.