According to AAA, the average price for a gallon of unleaded regular in the U.S. has increased 40% since the beginning of the year, rising from $2.25 on Jan. 1 to $3.147 on June 12. The increase in New Jersey was even larger, up to $3.165 a gallon from $2.178 a year ago.

And AAA believes the price of a fill-up will continue to climb, by 10 to 20 cents through the end of August.