Travelers who waited to make Thanksgiving trips are hitting the biggest crowds so far

Travelers who waited until the last day to make their Thanksgiving holiday treks need to be prepared for busy highways and the most crowded day yet this week at the nation's airports.

The Transportation Security Administration expected to screen 2.9 million people on Wednesday and more than 3 million Sunday, when many holiday revelers plan to return home.

Air travelers had reason to give thanks — fewer than 50 U.S. flights had been canceled by midafternoon on the East Coast, according to FlightAware.

However, more than 2,000 flights were running late, reflecting the tendency toward tardiness that is becoming normal at U.S. airlines. They were averaging more than 4,500 late flights per day since last weekend, and Wednesday's count was likely to approach or surpass that number by nightfall.

Wednesday afternoon was expected to be the worst time to travel by car, according to forecasters. Drivers headed out of town will be mixing with commuters unlucky enough to be working on the day before the holiday.

Accidents compounded the heavy traffic. A dump truck that struck a bridge over Interstate 95 in Delaware closed the highway for several hours, according to the Delaware Department of Transportation.

Patience is the key

''Let them be in a rush. Let them do their thing. You're prepared,'' Spainhower said. ''You're ready for people to push and shove and want to get to their flight because they showed up late, but you just need to be relaxed and hang out. You're not going to get anywhere faster. The plane is not leaving any earlier.''

Joan Fischer of Montclair, New Jersey, and her husband flew to Chicago to visit grandchildren and were surprised at how easy the trip was.

"We flew out of Newark" — an airport notorious for delays — ''and you wouldn't know it was a holiday,'' Fischer said. "It was well run, and it was really not busy.''

Weather is a wild card

An Arctic blast in the Midwest and wet weather in the Eastern U.S. could disrupt travel over the next several days.

Forecasters expect clear weather over most of the western two-thirds of the country on Thursday and Friday, but rain and possibly thunderstorms are predicted for the Southeast, which could raise the risk of flight disruptions.

Thanksgiving, by the numbers

Auto club and insurance company AAA predicted that nearly 80 million Americans would venture at least 50 miles from home between Tuesday and next Monday, with most of them will traveling by car.

Drivers should get a slight break on gas prices. The nationwide average price for gasoline was $3.07 a gallon on Wednesday, down from $3.25 at this time last year.

Airfares, however, are about 4.1% higher than they were a year ago, according to government figures.

The TSA expects the biggest crowd on Sunday, which could break the record of 3.01 million set on the Sunday after the July Fourth holiday.

FAA staffing shortage could create delays

TSA Administrator David Pekoske said his agency is ready, with its highest staffing ever, but an ongoing shortage of air traffic controllers at the Federal Aviation Administration could cause flight delays.

FAA Administration Administrator Mike Whitaker said last week that his agency likely will use special measures to deal with shortages at some facilities.

''If we are short on staff, we will slow traffic as needed to keep the system safe,'' he said.

The FAA has long struggled with a shortage of controllers that airline officials expect will last for years, despite the agency's lofty hiring goals.

Holiday travel myths

While many people believe that flight delays and cancellations are worse during the holidays, the data doesn't bear that out, online travel company Kayak said. Last year, the rate of canceled flights was about five times greater in July and August than it was during Thanksgiving and nearly three times greater than the Christmas period, according to FlightAware data.

''But people's tolerance for those delays is significantly worse'' during the holidays, Kayak CEO Steve Hafner said.

When airports struggle during the holidays, Hafner said, it's often because they are busy, prone to winter storms, or subject to shortages of FAA air traffic controllers.

Celebrating the holiday overseas

Some Americans are discovering that Thanksgiving can be a relatively inexpensive time to fly overseas.

''Airlines struggle to get people on these international flights, and they are trying to have less losses by offering some fantastic fares,'' Katy Nastro of the travel site Going.com said.

International trips over Thanksgiving aren't for everybody.

''I don't see a lot of young families doing this because Thanksgiving is a very familial holiday, seeing family and friends,'' Nastro said. ''It's single people, couples ... people who work remotely."

TSA says it's OK to bring turkey, stuffing and other favorite holiday foods through airport checkpoints, although liquids such as gravy and cranberry sauce can't exceed 3.4 ounces.

Just because you can carry it on the plane doesn't mean you should.

''Especially when it comes to gravy, I wouldn't want that in my carry-on luggage, and I definitely wouldn't want it in my checked baggage,'' TSA spokesperson Lorie Dankers said.

Thanksgiving brings out infrequent flyers, and they often have questions about what they can bring on the plane. The TSA app and website have lists of items that are banned or restricted.

Drive time

On the return trip, the least-congested times to drive will be before 1 p.m. Sunday and before 8 a.m. or after 7 p.m. Monday, the company said.

In metropolitan areas like Boston, Los Angeles, New York, Seattle and Washington, ''traffic is expected to be more than double what it typically is on a normal day,'' INRIX transportation analyst Bob Pishue said.

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