Liz Daniel, charter manager at Landmark Aviation in Raleigh-Durham International Airport, said calls for charters are up 30 percent to 40 percent since British authorities uncovered an alleged plot to blow up planes.

"We've had a lot of calls," Daniel said Tuesday. One caller had elderly parents not up to standing extra time in security lines. Another's husband was disabled. But chartering isn't a cheap alternative. Daniel said it costs $1,500 to $2,000 an hour to rent a twin-engine King Air turboprop plane, while a private G4 jet runs $4,000 an hour. Still, some callers are considering chartering planes for longer transcontinental or international flights, Daniel said.

Caleb Tiller, spokesman for the National Business Travel Association, an Alexandria, Va. group representing business travelers, including many corporate travel managers, said airlines could begin canceling flights if long waits continue in security lines and for flights. In a continuing online poll, 50 percent of the association's members said they planned to decrease business flights.

But whether it's a substantial travel decrease will depend on how long the added inconvenience persists, said Tiller, who expects things to return to normal soon.

"There will be some slight decrease in commercial air travel as long as the heightened security measures are in place," Tiller said, "but every indicator leads us to think this is a temporary situation." For example, travelers in the United Kingdom now can bring a carry-on bag; last weekend, they couldn't.

"For some people, it's been an inconvenience, but most people expect it to get back to normal soon," Tiller said.