As Memorial Day approaches, gas prices are on the rise again on Long Island.The average price Wednesday for a gallon of regular gas on the Island was $2.43. Last month, the average price was $2.16.The average price last year at this time, however, was $3.97.Experts say gas prices could continue to increase as Memorial Day approaches. AAA expects more than 32 million people to travel this year, the first increase in four years.