The AAA estimated that 38.3 million people would travel 50 miles or more for Thanksgiving — up a million from last year.
Moderating gas prices may be one reason for the increase, said the automobile association's Robert Sinclair.
Since peaking above $3 per gallon in early August, gasoline pump prices have dropped by around 80 cents per gallon nationwide in the past three months. Wednesday's nationwide average gas price was $2.23 a gallon, according to AAA.
Thanksgiving air travel was expected to surge, too. AAA predicted 4.8 million travelers will fly to their Thanksgiving destination. The Port Authority of New York and New Jersey anticipated 1.6 million passengers — about 2 percent more than last year — would pass through LaGuardia, John F. Kennedy International and Newark Liberty International airports.
During the height of the travel weekend, that means there could be as many as 6,000 planes flying over the United States at one time, reports CBS News correspondent Bob Orr.
The biggest challenge so far has been the weather, adds Orr. A storm system is causing delays from Charlotte, N.C., all the way to Boston.
By early afternoon Wednesday, arrivals at LaGuardia and Newark were late an average of an hour due to the storms in other parts of the country, said Steve Coleman, a spokesman for the Port Authority.
At Boston's Logan International Airport, wait times at security checkpoints were averaging less than 10 minutes and there were no long lines at ticket counters at midday.
Complicating air travel are the new restrictions that are forcing passengers to check more of their luggage, resulting in hundreds of thousands of extra bags being checked — at Chicago's O'Hare Airport alone, reports CBS News correspondent Cynthia Bowers.
This could translate into more missing luggage. The rate of lost and mishandled bags has doubled in the last year. At O'Hare alone, that means more than 16,000 misplaced bags for Thanksgiving week, reports Bowers.
And many of the passengers traveling this weekend are infrequent ones who are not used to the new rules allowing allow passengers just 3 ounces of a liquid or gel to be carried in a one-quart bag, Bowers adds.
The holiday rush comes as Homeland Security Department formally announced Wednesday that virtually all air travelers entering the United States after Jan. 23 — even U.S. citizens. Until now, U.S. citizens, travelers from Canada and Bermuda, and some travelers from Mexico who have special border-crossing cards for frequent visitors were allowed to show other proofs of identification, such as drivers' licenses or birth certificates.
Meanwhile, air travelers faced a potential nightmare when baggage handlers for Northwest Airlines Corp. stopped working in its Detroit and Minneapolis hubs on Wednesday in a dispute over who will clean airplanes, a union official said. A spokesman for Minneapolis-St. Paul Airport says Northwest Airlines baggage handlers are working again after a brief work stoppage that lasted about half an hour. Spokesman Pat Hogan said the stoppage began around noon, but that all the handlers returned to work. He said there's no initial indication that it caused delays or other problems at the airport.
Drivers in parts of North Carolina, South Carolina and Virginia faced high winds and flooded roads Wednesday as an early winter storm swept across the South.
The weather slowed traffic between the Carolinas on Interstate 95, one of the main arteries for East Coast travel. Some ferry service along North Carolina's coast was halted on Wednesday due to the storm; the state Department of Transportation said it would likely not resume until Thanksgiving Day.
In Virginia, a tunnel between Norfolk and Portsmouth was shut down because of high water, and high winds prompted operators of the Chesapeake Bay Bridge-Tunnel to limit vehicles crossing the span to cars and pickup trucks.
Motorists along Interstate 40, an east-west highway that spans more than 2,500 miles, were seeing more than just fall colors along the route: State troopers will be posted every 10 miles.
The coordinated effort between state police in the eight states the highway passes through — California, Arizona, New Mexico, Texas, Oklahoma, Arkansas, Tennessee and North Carolina — is aimed at reducing accidents and fatalities Wednesday and Thursday.
In New York, scores of people packed the train waiting area at Pennsylvania Station by noon, including Sandra Clifton. Her flight last year to Pittsburgh took so long — 27 hours thanks to flight cancellations and delays — that this year she was taking the train to see different relatives outside Philadelphia.
"It broke my mother's heart," said Clifton, 39. "I love my family. I just can't always get to them."