The Thanksgiving holiday travel period officially begins at 6 p.m. today, although many motorists are already on their way.

The state Department of Public Safety is urging drivers to use extra care as they face unfavorable weather in many areas.

Officials say Thanksgiving is already one of the most heavily traveled holidays, and the inclement weather could create even more hazardous driving conditions.

Last year, 10 people died in South Carolina collisions during the period from Wednesday night through Sunday evening.

An estimated 567,000 South Carolinians are expected to drive at least 50 miles from home this Thanksgiving holiday.

When many of those travel plans were made, gas prices had fallen several cents to below $3 per gallon.

But this week, fuel prices jumped 10-to-15-cents or more.

Angela Daley with AAA Carolinas cited a couple reasons for the fluctuations.

First of all, crude oil prices, which have come up a little bit and really haven't headed down as we would have expected for the fall,” she told the South Carolina Radio Network.

“And then also, we've had some refinery issues in the Gulf and that's tightened the supply.  And when that happens, you'll start to see gas prices rise.”

While it had appeared Thanksgiving travel would be noticeably cheaper than last year, the average price for a gallon of regular gas in Columbia is now at least three cents higher than one year ago.

Daley says the ups and downs in pump prices will continue until certain things happen in the energy industry.

If the refineries can get back on line and supply levels return back to normal...and depending on where crude moves...and also the nuclear deal with Iran will definitely help push crude oil prices lower – it's just a matter of how much.”

She says the highest number of motorists traveling for Thanksgiving will depart today and most travelers are expected to return on Sunday.