And in the day's other news: On this day before Thanksgiving, a major winter storm and a plunge in temperatures is wreaking havoc with many travelers' schedules.

Flight delays are piling up.

And, as John Yang reports, temperatures will drop to 20 degrees below normal in much of the Central and Eastern parts of the country.

JOHN YANG: In the Upper Midwest, a heaping Thanksgiving serving of snow.

Overnight, blizzards blanketed the Great Lakes with more than a foot-and-a-half of snow in some areas, making highways dangerously slick, like this one lined with tractor trailers in Western Minnesota.

It's part of a storm system hitting the Midwest and the Northeast with wet, windy weather as millions of Americans buckle up for holiday travel.

AAA says about 90 percent of Thanksgiving travelers across the country will drive.

Traffic jams are all but certain.

MAN: Traffic became a parking lot.

It tacked on another four hours.

JOHN YANG: Others will fly in what's been a turbulent period for air travel caused in part by the government shutdown.

The FAA is anticipating the busiest day in 15 years, with more than 360,000 flights scheduled throughout the week.

According to FlightAware, by late today, about 4,000 domestic and international flights were delayed at U.S.

airports.

That's almost one in ten.

SEAN DUFFY, U.S.

Transportation Secretary: Let's all be better when we travel together.

JOHN YANG: The secret to a smooth travel day?

Transportation Secretary Sean Duffy says it's a respectable outfit.

He was interviewed by The Blaze about his new civility campaign.

SEAN DUFFY: I get being comfortable.

We like being -- we're in an era where people don't wear suits as much anymore.

They don't wear ties as much anymore.

At some point, we can't dress like we're going to bed.

JOHN YANG: For many travelers, flying smart is key.

And in the end, being with family is always worth the chaos.

WALKER POWELL, Traveler: Preparing for travel for Thanksgiving week really comes to long-term preparation of thinking about when we're going to fly, what time of day is it going to be, what day is it going to be.

With our family living in Louisiana and us in Colorado, we don't get in to that many times to see each other, especially with the kids seeing their grandparents.

You have got to take advantage of any opportunity you get.

JOHN YANG: For the "PBS News Hour," I'm John Yang.