U.S. self-serve gasoline prices rose sharply in the first week of 2006 and could hit $2.50 a gallon in the next few weeks as the cost of crude oil climbs, according to AAA, the nation's largest organization for motorists.

The nationwide average price forself-serve regular gasoline now stands at $2.322, about 15.1 cents higher than mid- December, and 55 cents higher than one year ago, AAA said.

Prices shot up 9.8 cents per gallon in the last week, as crude oil prices also increased to near $64 per barrel, AAA said.

AAA said most of the increase in gasoline prices can be traced to higher prices for both crude oil and wholesale gasoline.

"Unfortunately motorists that were feeling good about gasoline prices falling in December, now face the prospect of higher prices in the new year," AAA said.

Although the Orlando, Fla.-based organization said 2006 prices may not revisit highs reached after Hurricane Katrina, consumers should begin budgeting for higher fuel costs.

"Prices typically increase in the spring," AAA said, noting that supply tightens with the start of seasonal refinery maintenance shutdowns.

"Even a modest series of price increases could easily take the price of gasoline near $2.50 per gallon later this year," AAA warned.

Nationwide, the price of self-serve, mid-grade gasoline now averages $2.465 per gallon, an increase from $2.304 per gallon in the middle of last month, and up from $1.881 one year ago.

Self-serve premium averages $2.554 per gallon, up from $2.338 per gallon one month ago and $1.950 higher than one year ago.