The national average price is forecast to fall - by just one cent - to $3.57 per gallon between April and September, the months when Americans do most of their driving.
Still, that would be the lowest average since 2010. For the year, the Energy Department's Energy Information Administration expects gasoline to average $3.45 per gallon, down from $3.51 last year and also the lowest since 2010.
World demand for oil is growing, but supplies are growing faster than demand, thanks to higher production in the U.S., Canada and elsewhere. That will keep a lid on the price of crude and gasoline.
The price of Brent crude, a benchmark used to price oil used by many U.S. refineries and the most important factor in gasoline prices, is forecast to fall 4 percent this year.