Why is Thanksgiving travel on the rise?

Credit falling gas prices and an improved economy for the heavier traffic you're likely to encounter on Southern California roads as you make your way to Thanksgiving dinner.

The Automobile Club of Southern California is predicting that 3.5 million Southland residents will travel over the holiday -- between Wednesday and Sunday -- a 3.8 percent increase over last year and the highest volume since 2007 when 4 million traveled at least 50 miles from home. Statewide, more than 5.6 million will be getting away for the holiday.

One of the factors fueling the increased travel is the steady drop in the cost of gasoline, with prices in Southern California heading toward an average price of $3 a gallon. They're currently about 40 cents lower on average than at this time last year.

"As Californians see improvements in jobs and household worth this year, they are more willing to spend on travel,” Auto Club spokesman Jeffrey Spring said Monday. "An added bonus for travel budgets has been dramatically lower gas prices in the past two months. Consumers have more money in their pocket to plan trips, and this Thanksgiving’s travel will cost them less by car and just 1 percent higher than last year on average by air.”

Unlike last year, when San Diego was the top destination for Southern California travelers, it has fallen to No. 3 , behind Las Vegas and San Francisco. The last time San Diego was the No. 3 destination was in 2006, according to the Auto Club.

For both Southern California and the state, the majority of travelers -- 85 percent -- are expected to drive, while 11 percent are forecast to fly. The San Diego International Airport is anticipating as many as 60,000 passengers a day during the holiday period.

Airport officials are advising travelers to arrive at least 1.5 hours early for domestic flights and 2.5 hours for international travel. As a bonus for this year's holiday season, the airport has partnered with Traveler’s Aid Society of San Diego and Therapy Dogs, Inc. to launch Ready, Pet, Go, a new therapy dog program

Meant to be a way to help relieve holiday travel stress, the program pairs up a therapy dog and handler to roam the terminals post security, visiting passengers awaiting flights.

Like Southern California and the state, there will be a sizable increase in the number of holiday travelers nationwide. Some 46.3 million people are forecast to travel, an increase of 4.2 percent from last year. A little more than 41 million will drive to their destinations, and 3.5 million are expected to fly, AAA reported.

The projected increase in travel comes even as some travel costs have increased. According to AAA’s Leisure Travel Index, hotel rates for AAA Three Diamond lodgings are expected to increase eight percent from one year ago with travelers spending an average of $154 per night compared to $142 last year.