With U.S. skies under tight control Wednesday, tens of thousands of stranded air travelers scrambled to find some other way to get where they needed to go.

A day after the terrorist attacks prompted the government to ground all commercial flights for the first time in history, rental car agencies were swamped, long lines formed at train stations and big airports were eerily quiet.

''It's just a big mess,'' said Brian Junker, 40, at Union Station in Indianapolis, waiting for a bus so he could complete a transcontinental journey to Los Angeles that was interrupted when his flight was forced to land in the Midwest.

The mayor of Boise, Idaho - Brent Coles - rented a car to drive the 1,800 miles back home from Little Rock, Ark., after giving a speech there. Four people hired a taxi at Chicago's O'Hare Airport for a $3,000, 30-hour ride back to Los Angeles. The Amtrak train from Tacoma, Wash., to Oakland, Calif., was full of riders talking about missed flights and comparing the attacks to Pearl Harbor.

People bought used cars in Chicago to drive home when they were unable to get rentals. There were even reports of air passengers renting U-Haul or Ryder trucks for their long one-way journeys home, without cargo.

Still, travel officials and travelers alike reported an absence of the angry scenes that often accompany fouled-up itineraries.

''I'm not complaining,'' said Brenda Abel of Yorktown, Va., who was taking a train home from Chicago. ''This has upset me inside, but my problems are minimal,'' she said. ''I'm alive.''

On Wednesday afternoon, the government lifted some restrictions, allowing people whose flights were diverted during the terrorist attacks to resume their journeys. But other planes were kept grounded.

By then, however, many stranded passengers were already heading home by other means or making arrangements to do so.

Other travelers just decided to wait for the air shutdown to ease. Some travelers had little choice but to wait, their flights having been diverted to such far-flung spots as Newfoundland, Canada.

The travel problems were clearly apparent in Chicago, one of the world's busiest transportation hubs.

O'Hare was virtually deserted Tuesday morning, with only a dozen travelers in evidence. For security reasons, passengers were not allowed to sleep on the airport concourse.

Many instead spent the night in hotels up to 40 miles away, and worked the telephones to try to find some other way of transportation.

The Red Cross set up shelters and help stations in cities and airports in 11 states, providing food and counseling. Spokesman Darren Irby said the move in so many airports at once was unprecedented.

About 25 people attended a Catholic Mass at O'Hare, including Christina LaClair of Mesa, Ariz., who was stranded while returning from Burlington, Vt.

''I'm here to pray for other people who weren't so lucky,'' she said. ''But it also gives me peace of mind to get on that airplane.''

Amtrak said its ridership swelled nationwide during the crisis. It operated two additional trains out of New York on Wednesday and said it had twice as many passengers on its Washington-New York train as usual. The railroad honored airline tickets for travel to cities it serves.

At Chicago's Union Station, Bob and Tina Papke of Seattle clutched pillows and dragged a large suitcase as they waited in a line of about 50 people to buy train tickets. They rented a car to get out of New York on Tuesday and drove to Chicago to catch a train home - a trip that left them exhausted but still thankful.

''You saw that pillar of smoke rising and all these people walking away and you felt fortunate,'' Bob Papke said.

North of the border, more than 200 jetliners heading for the United States on Tuesday were diverted to Canada. Some passengers stayed in their planes overnight, while others slept in hotel corridors, in the beds of strangers or on cots in school gyms.

In remote Gander, Newfoundland, 38 planes carried in 6,500 passengers Tuesday, not much less than the town's population of 10,000.

More than 300 people on a charter flight from Manchester, England, to Orlando, Fla., were taken to St. Paul's Intermediate School in Gander after spending 22 hours on the tarmac without being told why.

''We were really in the dark. We did not know how serious it had been until we got off,'' said George Gemmell of Scotland.

Ben Bowen, 44, of England praised the people of Gander for making passengers feel welcome.

''It's been a bit of an ordeal, but the help we are getting is tremendous,'' he said. ''The townfolk here can't do enough for us.''