A downward trend in gas prices is perhaps picking up momentum, with the average national cost per gallon dropping by 11 cents in a week, Idaho AAA announced Monday.

The trend was also apparent in the Northwest, with the average price in Idaho going down by 9 cents, to $4.05 per gallon, and Washington seeing an 11-cent decline, to $5.02 per gallon.

“Hopefully, this is the signal that the floodgates are about to open and real savings will start pouring in,” AAA Idaho Public Affairs Director Matthew Conde said. “We could see the state average drop below the $4 mark in a matter of days, and in some parts of Idaho that’s already the case.”

It remains expensive to fill up in the Northwest, with Idaho having the eighth-highest average fuel price and Washington ranking second, according to AAA. California has the highest average at $5.80 per gallon.

The cheapest gas in the Lewiston area Monday was at the Conoco station near the Clearwater River Casino, where the price was $3.79 per gallon, according to GasBuddy.com. Other stations in the Lewiston Orchards were selling fuel for $3.98 per gallon.

In Moscow, the cheapest price was $4.09 at the Sinclair station along the Pullman Road, according to GasBuddy.com.