Both bustling crowds and bad weather are expected to be obstacles for more than 80 percent of Americans are expected to be on the move over the Thanksgiving holiday. That's 3 percent more than last year.
The snow caused dozens of flight cancellations and three-hour delays at Chicago's O'Hare International Airport, where city officials expected more than 1.4 million travelers to pass through by Sunday night.
La Guardia airport is reporting average delays of about 45 minutes. A combination of bad weather and heavy passenger loads is causing incoming flights to be delayed by an average of an hour and a-half at Atlanta's Hartsfield-Jackson International Airport. Some flights have been diverted elsewhere.
And these air delays could worsen: Thunderstorms are striking the southeastern United States and will be sweeping up the East Coast before the weekend.
In Michigan, a Northwest Airlines jet carrying 87 passengers and four crewmembers slid off a snow-slickened runway while landing at Lansing's Capital City Airport. No one was injured. Bad weather forced Northwest Airlines to cancel a total of 37 flights, including 22 into or out of Detroit.
The snowfall was accompanied by high winds in spots. The National Weather Service reported gusts of 57 mph around Champaign, Ill. High winds along Interstate 74 near Greensburg, Ind., caused a semi trailer to overturn, leaving the highway strewn with debris.
The situation isn't much better on the ground. Traffic on the state's highways is bumper-to-bumper as travelers deal with soggy roads and — in some areas — tornado damage.
The National Weather Service said parts of Illinois got up to 8 inches of snow, while 7 inches were reported outside Kansas City in the Midwest's first major snowfall of the season. The region was also hit by strong thunderstorms, high winds and icy conditions that made driving treacherous.
"We're seeing out of the 37 million people that are going to be traveling; about 30 million are going to be traveling by car," the American Automobile Association's Aymee Ruiz told CBS News Early Show co-anchor Hannah Storm. Most trips will be from 50 to 300 miles.
Traditionally, the Wednesday before Thanksgiving is always the busiest travel day of the year, and AAA expected travel this year to hit pre-Sept. 11 levels for the first time since the tragedy.
Linsdell and Rita Pikes arrived in Atlanta more than an hour behind schedule on their flight from Baton Rouge, La.
"We had a little delay when we left and we had to make a few circles when we got here," Pikes said. "We've seen so many of those planes waiting to take off, it wasn't funny. I wouldn't want to be in their shoes."
Security was visibly tighter at Washington's Reagan National Airport and lines snaked two-thirds of the way down the main concourse.
There were no delays by late morning at Chicago's O'Hare Airport, the nation's busiest, said spokeswoman Annette Martinez. City officials expect more than 1.4 million travelers to pass through O'Hare by Sunday night.
However, 6 inches of snow was possible in the Chicago area as a second storm streamed into the region from the Plains. By mid-afternoon, snow was falling from Michigan into Kansas, where more than 7 inches of snow had fallen outside Kansas City.
Motorists cruised through Pennsylvania Turnpike toll plazas for free Wednesday after toll collectors and maintenance workers went on strike hours before the holiday rush.
For the airlines, David Stempler of the Air Travelers Association expects a bumper crop of passengers — and hassles.
"The number of passengers is probably going to be the strongest since the Year 2000," Stempler told CBS Radio News. Air traffic might even surpass pre-Sept. 11 levels, he said.
The heaviest Thanksgiving travel — 41.6 million Americans — occurred in 1995, according to AAA, the Orlando-based travel agency.
Security is visibly tighter at the airports. Screeners for the Transportation Security Administration at Washington's Reagan National Airport were using a public address system to tell travelers what they needed to do to keep the lines moving. Passengers were also being asked to remove all outer layers of clothing and to take cigarette packs and candy bars out of their pockets.
"It's an encouraging comeback for the travel industry because air fares, hotel rates and gas prices have all gone up in the past year," said Kris Lathan, spokeswoman for AAA Chicago.
Gasoline prices will be the highest-ever for a Thanksgiving holiday period, nearly half a dollar above last year. The national average was $1.97, according to the Energy Department.
Those traveling through Pennsylvania could save some money, though. Turnpike toll collectors have gone on strike heading into the busy holiday travel season. The turnpike commission anticipated a walkout and decided to waive tolls Wednesday. They plan to have non-union workers staff the booths Thursday.
According to AAA, approximately 12 percent, or close to 5 million, of Thanksgiving travelers expect to fly to their respective destinations. In spite of the 3 percent increase in airfares over the last year, the number of Americans who will fly this Thanksgiving represents a 3 percent increase over last year.
FAA spokesman Greg Martin said the nation's aviation system, which has seen a 52 percent spike in delays this year because of bad weather and rising demand, should operate more efficiently than it did a year ago. That's because some of the largest airlines have "de-peaked" their schedules, or smoothed out the flow of traffic more evenly throughout the day, particularly in busy cities such as Chicago, Dallas and Atlanta.
Still, "passengers should expect to find lines everywhere - at baggage check-in, ticket counters and at the security checkpoints, so give yourself plenty of time and that will protect you," Stempler told CBS Radio News.
"Clearly, ridership is up," he said. "People are paying fairly low fares, so especially older legacy carriers are still struggling to make a profit at these fare levels."
However, at the Orlando airport, "the lines weren't nearly as bad as we expected," reports CBS News Correspondent Peter King. The longest lines were those inside the terminal at check-in. "People are really getting an edge by checking in at curbside, because there are almost no lines there," King said. "We got through check-in in less than 5 minutes. The security lines were not that long, and they moved very quickly" because of extra personnel.
In the aftermath of the March train bombing in Spain, Amtrak passengers can expect to see a greater police presence than in past holiday seasons but won't have to pass through metal detectors.
Federal transportation security officials are warning air travelers that there'll be more vigilance — and more personal checks - of passengers during the holiday period this year, an outcome of the in-flight bombing of two Russian airliners last summer.
Officials said Tuesday there'd be more "pat-down" searches and more people chosen for screening, even if they don't set off alarms at security checkpoints.
"What I recommend, especially for men who tend to carry a lot of change, their cell phones and keys in the pocket, grab a zip-lock baggy as you head out of the house and put all of that in your zip-lock baggy," then put it on the scanner belt, Travelocity editor-in-chief Amy Ziff told CBS News Early Show co-anchor Reneé Syler.
The AAA also finds that hotel rates are up compared to last year. However, only some 23 percent of holiday travelers expect to utilize hotels and motels, as the vast majority, 63 percent, expect to stay at the homes of relatives or friends.
"Most travel-related costs are up compared to last year," Lathan says. "Still, most trips will cost less than they did in 2000 mainly due to increased competition from discount airlines and the fact that hotel rates are only just starting to rebound from recessionary lows."
The extra cost isn't stopping holiday travelers, reports CBS News Correspondent Kelly Cobiella, but the weather might: Flooding rains in Texas, paralyzing snow in New Mexico and another storm brewing in the Midwest.
The Midwest will be the starting point for nearly 7 million auto travelers and about 700,000 air travelers. Small towns and rural areas are the intended destinations for 40 percent of all Thanksgiving travelers, followed closely by cities at 36 percent.
The weather was also disrupting travel in the Northeast. Airports in New York City, Boston and Newark, N.J., were experiencing delays up to two hours because of rain.
Adriano Maniaci's flight from Orange County, Calif., was an hour late getting into O'Hare, but she was happy to make it there safely.
"I just can't wait for tomorrow now to be with my family and eat lots of turkey," said Maniaci.