The two holidays when travelers least allow rising gasoline prices to impact their plans – Christmas and New Year’s – are offering up plunging prices at the pump.

So much so that, by the time everyone reaches grandma’s house, regular gasoline should cost below $3 a gallon on average at most Palmetto State gas stations, experts say.

Regular gasoline already has dropped below $3 a gallon in several pockets of the state, including scattered stations in the Midlands, and travelers should expect that trend to go statewide soon, according to AAA Carolinas.

“Right now in South Carolina, it’s $3.017 a gallon, and yesterday it was $3.023, so it’s falling by about a half-cent a day,” Charlotte-based AAA Carolinas spokesperson Angela Vogel Daley said Thursday. “If that continues for the rest of the year, it is likely that we will hit (an average) below $3.”

Gas prices in South Carolina have dropped significantly, Daley said, down 60 cents a gallon since mid-September and 9 cents a gallon since Thanksgiving.

Lower demand and higher inventories are credited for the falling prices, which may not last long. The Christmas-to-New Year’s travel holiday runs from Dec. 22 through Jan. 1 – an expansive 11-day period. As travelers move into the long holiday week, prices may stabilize as demand rises, Daley said.

For now though, the trend is down.

“We don’t see anything on the horizon that would cause gas prices to go up, other than the travel holiday,” Daley said.

Holiday travel in South Carolina is projected to increase this year by 2 percent in part because of lower gas prices and airfares, AAA Carolinas said.

About 1.3 million South Carolinians are expected to travel more than 50 miles from home over the Christmas-New Year’s holiday – about 1.1 million, or 90 percent, driving.

South Carolina has the third-cheapest gasoline in the United States, AAA Carolinas said.

The state’s average price per gallon would be lower but for gas prices in Charleston, Daley said, where regular-grade gasoline costs top $3.10 on average.

Spartanburg has the state’s lowest average price per gallon at $2.94.

Gas prices in neighboring North Carolina and Georgia are higher.

Even if gasoline prices stabilize, the lower prices should hold beyond January, possibly until closer to spring. That’s when refineries typically switch to more expensive fuel blends in preparation for the summer, which usually means higher prices, Daley said.

But prices could rise if the “fiscal cliff” is averted, Daley said. A deal likely would lead to a stronger economy, increasing demand – and prices – for fuel, she said.