After years of getting hosed at the pump, some Bay State motorists could soon be paying a road-trip- ready $3 a gallon for gas — a four-year low — as North American and Middle East oil supplies rebound and the Chinese and European economies cool down.

“Early this winter, we could see gas prices go near $3 a gallon, but the national average should end up around $3.10,” said Michael Green, spokesman for Florida-based AAA.

Supplies have been building up, driving down prices just as the leaves begin to turn, added Michael Lynch, president of Strategic Energy & Economic Research in Winchester. The lowest Massachusetts gas price yesterday was $3.02 a gallon at Sal’s Gas & Repair in Holbrook, according to Gasbuddy.com.

“We’re definitely on a downward trajectory,” Lynch said. “We’ve seen recovery in supply from Libya and economic weakness in China and Europe. There’s no real bullish news on the horizon. … (But) there seems to be no political threats to oil supplies at the moment — which of course can change pretty quickly. In all likelihood, the weakness is going to continue for several months.”

A boom in North American petroleum production also has eased supply problems, AAA’s Green said.

“The other half of the equation is we’re using less gasoline in the United States due to decreased driving and increased fuel conservation,” he said. “Until we see the economy fully recover, we may not see driving return to what it was” at its 2007 peak.

The national average gas price last reached $3.10 per gallon in January 2011. It hasn’t dipped below $3 since December 2010. Last year, it hit a low of $3.18 on Nov. 12.

This year’s average price may not fall below $3 in Massachusetts, however, due to higher gas taxes and no nearby refineries with access to domestic crude oil, Green said.

In 2013, Bay State prices bottomed out at $3.33 on Nov. 12. Yesterday’s average price was $3.39 — making Massachusetts the 21st most expensive state for gas.

“Given that … it looks nearly certain that prices in Massachusetts will fall below what drivers paid last year,” Green said. “Consumers may luck out and see gas prices in Massachusetts drop another 20 cents per gallon by Thanksgiving.”

The average gas price reached a high this year of $3.70 nationally on April 8, with a Massachusetts high of $3.73 on July 2.

“Gas prices are very seasonal,” Green said. “They’ll hit a low sometime probably in early winter and then rise back to levels that many people do not want to pay.”