AAA is warning motorists that gasoline prices could increase as much as 40 cents per gallon this summer. They say that declining gasoline reserves could possibly trigger the cost gain. But they also look for an increase in domestic production of fuel to put a cap on historic gasoline hikes this spring. The average price for a gallon of unleaded gas in Tennessee is currently $2.09. In Crossville, the lowest cost for a gallon of unleaded gas is $2.05. Drivers in Rockwood are also seeing that same low price currently.