Air, road and rail travel have surged to levels not seen since before Sept. 11, 2001, during a summer in which Americans have renewed their love affair with traveling despite terror warnings and high gas prices.

Indications of increased travel abound. Hotel occupancy rates are climbing, ridership on trains is setting records and drivers have been taking to the highways. But nowhere has the rebound been more apparent than at airports.

Nearly 1.5 million people flew in or out of Reagan National Airport in June, an increase of almost 13 percent over last year. The demand has strained the airport's parking capacity. Its daily lots and garages have filled on a handful of occasions, while the economy lot is regularly sold out, airport officials said.

Nearly 2 million passengers passed through Baltimore-Washington International Airport in June, a 5 percent increase over the same month last year. Dulles International Airport also approached 2 million in June, a 21 percent increase.

"We're continuing to be very busy and we think that's only going to rise," said Tara Hamilton, spokeswoman for the Metropolitan Washington Airports Authority, which manages Dulles and National. Hamilton added that she expects the July and August numbers to be just as strong.

But that's not good news for such regular fliers as David Henderson, who has given up on Dulles because it's become too crowded for him. On a recent trip to California, for instance, he flew from National even though there was a direct flight from Dulles, because "it is just absolute chaos and confusion at its worst."

"I think it's maxed out its capacity operationally," said Henderson, a senior vice president for the National 4-H Council who flies about 100,000 miles a year.

The stresses on Dulles come from all directions. It is the region's hub for international travel; its general aviation services have grown since the terrorist attacks shuttered those operations at National; and its domestic service is adding several hundred takeoffs and landings a day.

Some passengers fume about the time it takes for buses to travel from the main terminal to the farthest-away new gates, which rest at the distant end of a midfield terminal, and about the crowding once they arrive there.

Also complicating travel at Dulles this summer: One of the airport's three runways has been closed for repairs since the spring, and other construction projects have forced passengers to take circuitous and time-consuming routes to their gates.

Hamilton said operations should start improving this week, when the third runway is expected to reopen. She also said things would get better in the fall and winter as demand tempers.

"I don't think we'll see the type of crowding there is today," Hamilton said.

Dulles is not alone. Federal transportation officials threatened to impose schedule changes at Chicago's congested O'Hare International Airport this month because of chronic delays there.

"It's busy everywhere," said Terry Trippler, president of the travel Web site "This summer was the catalyst. This was the tipping point" in returning to pre-Sept. 11 levels, he said. "Pent-up demand was just there for this summer, and barring an incident, I don't see any downturn in it."

David S. Stempler, president of the Air Travelers Association, said demand is so high that passengers are "either in the middle seat or next to someone in the middle seat."

Stempler said there are "lines everywhere. There are lines at the ticket counter, lines at the security checkpoint, lines at Starbucks, lines at the gates, lines on the planes -- it's an experience filled with lines. Clearly there's been a lot of pent-up demand for vacation travel, which is what we're seeing this summer. The lid has kind of popped off the top of the bottle."

The number of travelers taking trains has also swelled. Amtrak officials said they have set ridership records for four months in a row, including 2.25 million riders in July.

At the end of those trips, many travelers are looking for places to stay. Hotel occupancy rates were up 3.3 percent in June compared to last year, and preliminary figures for July show a 2 percent increase over July 2003, according to Smith Travel Research. Washington area occupancy rates did far better than the national average, rising 5.8 percent in June. Overall, occupancy rates rose 4.3 percent for the first half of 2004, Smith Travel said.

Lon Anderson, spokesman for AAA Mid-Atlantic, said high gas prices have not deterred auto travelers and that, in fact, the sheer number of drivers has helped keep prices high. He also said preliminary reports indicate that a record number of drivers hit the highways over the Memorial Day and 4th of July weekends.

"This is the first time we've projected travel to be at pre-9/11 levels," Anderson said. "We're not only at them, but exceeding them."