Yesterday Elaine Beno's regular Friday AAA Hawai'i report showed gas prices in Honolulu had fallen for the 10th straight week to an average price of $2.51 a gallon.

Beno, AAA's spokeswoman in Southern California, was non-committal about when the trend could change.

"We don't know when it's going to level out," she said, keeping with AAA's policy of not making pump price predictions. However, she added one intriguing bit of information that offered a clue.

"I found it pretty amazing to have sent out that information this morning, and within an hour or so, the price of crude dropped another couple of dollars a barrel."

Light sweet crude, as it's called, was "at around $42 a barrel" when her report was filed.

"And it had settled at $40.81 a barrel in the time that I wrote that and had sent it out."

Beno said yesterday's average price per gallon in Honolulu posted a 70-cent drop from a month earlier when it was $3.21 a gallon. As a measure of that sort of accelerated nosedive, she pointed out that average cost on the same day a year ago, $3.32 a gallon, was 11 cents higher than it was last month.

"This has not been seen before," she said.

The recent rapid plunge in energy costs, including prices at the pump, has been unprecedented, and is happening in conjunction with the recent unrivaled rise in unemployment. Employers cut the jobs of 533,000 U.S. workers in November — the biggest monthly drop in 34 years.

Gasoline futures for January delivery closed below a dollar, with optimism about the nation's economic health in serious decline. It was the first close below $1 since 2006.

Veteran energy experts have watched goggle-eyed as the price of a barrel of oil has nosedived since its high of $150 four months ago.

No one believed crude would lose $100 in value between July and December, said Tom Kloza, publisher and chief oil analyst at Oil Price Information Service.

Some analysts believe demand could evaporate further early next year. "January is just going to be awful," said Kloza, citing expected additional layoffs after Christmas.

Gas prices in Hawai'i are running about 80 cents higher than on the Mainland. However, Island residents, who don't have home heating costs to worry about, enjoy the advantage of watching pump prices drop daily at the same time their monthly electric bills are coming down.

Barney Robinson, who operates Chevron stations in Kahala and near Honolulu International Airport, said rapidly descending gas prices offer relief for consumers and retail dealers as well.

Higher pump prices equal less money per gallon for dealers because of credit card fees, said Robinson. For example, those 2 percent charges are less costly at $2.51 a gallon than they are for gas at $4.39 a gallon — the highest average price ever reached in Honolulu on July 29 of this year.

According to Robinson, pump prices are affected by four main factors: supply and demand, competition, acts of nature and government intervention.

"What we're experiencing today, since the end of July when the bottom started falling out, is a function of supply and demand," he said. "In other words, too much supply and not enough demand is what's causing prices of crude to come down right now.

"And, of course, that's being reflected at the pump."

An example of government intervention affecting pump prices is the two-year, 4.5 percent excise tax exemption on gas the Hawai'i Legislature passed in 2007, said Robinson. What happens to the price per gallon after the exemption expires on June 29, 2009, remains to be seen.

Until then, though, it's a good bet the price of gasoline in Ho-nolulu could continue its downward slide.