David Clegern, a spokesman for the air board, said the California Energy Commission would have to review gas inventories to confirm there is a shortage and assess what effect the switch would have on air quality.
ApRoberts said that the commission has determined that the state has plenty of gasoline to meet consumer demand.
Gil Duran, a spokesman for Gov. Jerry Brown, said in an email that his office is "monitoring the situation closely."
While prices were higher everywhere in the state, there were variances. Yuba City had the lowest average price at $4.33, according to AAA, while San Francisco was highest at $4.60. Prices averaged $4.54 in the Los Angeles area, $4.52 in San Diego, $4.40 in Fresno and $4.36 in Sacramento.
A station at Vandenberg Air Force Base on the Central Coast was selling gas for $3.91, while the price was $5.69 at a station in Calabasas, outside Los Angeles.
Some stations ran out of gas and shut down rather than take the risk of buying gas at soaring prices only to be stuck with a glut of overpriced fuel if prices dropped or if customers refused to absorb the extra cost that would be passed along to them.
The price of diesel fuel has also increased, adding significant costs for truckers who typically put hundreds of dollars' worth of gas in their tanks. The average price for diesel statewide was $4.48 a gallon Friday — 35 cents more than a year ago, according to AAA.
At a truck stop and gas station off state Route 99, on the outskirts of Fresno, independent trucker Joel Vargas said if diesel hits $5 per gallon, he will probably stop driving because he would be losing money.
"With that kind of price, I won't be able to support myself and my family," he said.
Other residents were taking steps to cut their gas spending.
In Sacramento, restaurant owner Sandra Aboufares spent the morning calling around to find the cheapest price and wound up at a Costco where cars were lined up around the block to pay $3.93 per gallon. Aboufares said she and her husband have cut back on catering out-of-town events, and if prices continue to rise, they might have to suspend free delivery.
"We're trying not to add a delivery fee because you're competing against big chains," she said. "But when people ask for delivery, we say, 'Aw, could you pick it up?'"
Victor Parrott, of Irvine, lost his electrical engineering job at Boeing Co. more than two years ago and was already accustomed to planning his errands to maximize gas efficiency. Now, he said, he will have to cut back even more after paying $4.69 a gallon Thursday — 74 cents more than what he paid a week ago.
"It's killing our pocketbook. You can't budget for it because you don't know what it's going to be," Parrott said as he left a grocery store with his two toddlers. "You just have to put in less. Instead of a half-tank, you put in a quarter-tank."
Contributing to this report were AP writers Jonathan Fahey in New York, Sandy Shore in Denver, Juliet Williams and Hannah Dreier in Sacramento, Jason Dearen in San Francisco, Beth Harris in Burbank, and Gosia Wozniacka in Fresno; and photographer Damian Dovarganes in Calabasas.