U.S. gasoline prices at the pump fell to the cheapest in about a year-and-a-half on Monday, driven lower by sagging crude oil prices and excess supply of the fuel, market participants said. Nationally, gas prices averaged just under $2.42 a gallon on Monday, the lowest since late August 2017, according to data from the American Automobile Association (AAA). Gasoline futures on the New York Mercantile Exchange RBc1 were the lowest seasonally since 2015. Prices have changed course from earlier this year, when they hit seasonal four-year highs. (For a graphic on gasoline prices, see: tmsnrt.rs/2QH3OZA ) Plummeting oil futures have helped deflate gas prices. Crude has plunged about 30 percent since October as global supply has surged and demand growth has weakened. Further, analyst said excess supply of gasoline in the […]