Grandma has the easy part -- it's the getting there for Thanksgiving that makes everybody else crazy.

So, heeding the advice doled out annually by travel whizzes, many people who head out of town for Thanksgiving are now calling it more than just a long weekend.

Some are canceling appointments at work, skipping college classes and booking flights home as early as a week ahead. Others, haunted by memories of traffic jams past, plan to skedaddle early to avoid being swept along with the masses fleeing town Wednesday.

Wednesdays before Thanksgiving are "like the last days of Saigon," said Bob Cullinan, an online booking service employee in San Francisco who will fly home to Nebraska tomorrow rather than wait until the last minute. "I think I did that once. I don't think I ever want to do that again. It made hell look like Club Med."

Maintaining sanity was a major incentive for Joe Gentile and Ethel Madnick to depart Saturday night on their journey from Boston to Florida.

"I'd rather take a few extra days and do what we're doing and cruise right in," said Gentile, waiting to board an Amtrak train at Union Station yesterday.

Other reasons figured in, too, of course: their flexible work schedules, his fear of flying and lots of practice traveling all over the map to see four children. But, as they headed off to see Gentile's 21-year-old daughter, Amanda, in Orlando, there was also the matter of the Wednesday rush.

"I know people who have off Thursday and Friday," said Madnick, a part-time administrative assistant. "So they say, 'Why not take off the whole week? Why not beat the rush, because we know Tuesday and Wednesday are going to be a zoo.' "

Amtrak this year is putting 58 more trains on the tracks in the Monday-to-Monday Thanksgiving week, which is typically the busiest of the year, said spokesman Dan Stessel. He said the railroad has urged people to ride on any day except for the Wednesday before and the Sunday after, and many people now do.

But with most public schools in session through Wednesday and jobs to be done, most people have no choice but to leave town Wednesday. The data still suggest that's what most people do, making the Great Wednesday Getaway before Thanksgiving as much a holiday rite as expanding waistbands, football games and Thanksgiving parades.

Traffic experts predict that the day will unfold with the usual maelstrom of lines and more lines at airports, rail and bus stations and with interstates frozen by bumper-to-bumper traffic by lunchtime.

"You know that if you don't get out of town Tuesday, you're going to have a hard time getting out of town," said Bruce Williams, a spokesman for the Virginia Department of Transportation. "We see on our traffic cameras that traffic begins to back up around noon on the Wednesday before Thanksgiving."

Thanksgiving is the ultimate expression of the importance of showing up -- and then chowing down -- with kin who are usually scattered. No other holiday seems as necessary in a time when modern families, already dissolved and recombined in arrangements unheard of a few years ago, are also so mobile.

"Thanksgiving has, I think, a kind of special place in that regard, as a time for a kind of family reunion," said Gary Gerstle, a history professor at the University of Maryland who has studied American culture.

Having shed many of its religious and historic overtones, Thanksgiving also has become a festival with appeal to people of all backgrounds, he said, including newcomers to the United States. While other holidays such as Christmas and Easter have been saddled with more and more commercialism, Thanksgiving remains relatively straightforward and gift-free, thereby avoiding the elaborate, sometimes awkward, economy of buying and receiving presents. People might bring food, but mostly they bring themselves, he said.

"So in a way, it's become a story about a kind of affirmation of family," he said.

Surveys by AAA predict that 484,000 people in the Washington area will drive at least 50 miles this Thanksgiving, compared with 481,000 last year, said Justin McNaull, a spokesman for AAA Mid-Atlantic. Nationwide, AAA predicts 35.9 million people will pick up and go for the holiday, compared with 35.3 million last year.

Travel experts say people seem to be taking more time. Though some measures hint at an elongating holiday, the numbers are incremental. Some surveys suggest that people are just starting the holiday earlier and ending it sooner.

"Everybody wants to be at Grandma's for Thanksgiving. That means they want to be on the road that Wednesday or earlier," McNaull said.

One of the arteries that clogs the fastest on Thanksgiving eve is the New Jersey Turnpike, where traffic is expected to peak Wednesday at 793,000 vehicles, up 7 percent from last year. The river of cars coursing over the four-to-14-lane superhighway also has appeared to be spreading itself over more days as people strive to beat the rush, a spokesman said.

"Over the years, more of them seem to be leaving earlier in the week or even the week before to avoid peak-period congestion," said Turnpike Authority spokesman Joseph Orlando. On the Wednesday, "the getaway is starting earlier in the day."

In the two-week period around Thanksgiving, flight departures show a slight increase for each of the three days before Thanksgiving, according to the U.S. Department of Transportation's Bureau of Transportation Statistics. About 21 percent of the flights during the fortnight are scheduled in that three-day period, compared with about 5.4 percent on Thanksgiving itself.

Amy Ziff, an editor at Travelocity.com, said people still spend about five days away for Thanksgiving, compared with seven days or so for Christmas.

At Hood College in Frederick, administrators threw in the towel years ago on holding classes on the Wednesday before Thanksgiving. Bonnie Hagerman, a former student and later a professor at the school, remembers slogging home on Wednesday night after attending class that day. The shorter week, she said, "was met with great relief."

Of course, Mondays and Tuesdays have succumbed to the holiday mood, as the campus population thins and the stalwarts left behind attend in body, if not spirit. As a result, many professors now avoid scheduling projects or classes. But not all.

"There are some grinches," Hagerman said.

Andrea Hurtado, center, waits at Union Station to leave for New York on a business trip that also puts her where she wants to be for the holiday.