Consumers chose not to take 41 million trips over the past 12 months because flying is too much of a hassle, according to a new Travel Industry Association study.

The more than 100,000 trips a day that don't occur because of the hassle factor costs the U.S. economy an estimated $26.5 billion in foregone travel spending, TIA President Roger Dow said yesterday.

Dow said that estimate is probably low because it assumes only $700 as the average amount spent on travel services per trip. Nor was any effort made to determine how much money would have been spent by those who didn't travel on goods and services unrelated to the trip.

"What would be the economic impact of the traveler who did not attend that meeting, who did not make that deal, who did not buy that vacation home" because they never took the trip during which those things might have happened, Dow said during a conference call with reporters.

The association's members include restaurants, hotels, rental car companies, airlines, attractions, trade groups and travel promotion agencies.

The study found that frequent fliers — those who travel five or more times a year by air — are the most dissatisfied. Nearly half of all such frequent fliers — 48 percent — said they are dissatisfied with the air travel experience while only about a third of all travelers listed themselves as dissatisfied.

James Sherman, a mortgage banker from the Boston area, is among those frequent fliers who now finds himself trying to avoid flying whenever possible.

"I think about (not flying) every single trip I make," Sherman said. "The hassle factor has become extreme. I'm also booking more last-minute (flights) now because I wait as long as I can to decide if I really need to go. I've stayed in the Boston area four or five weeks so far this year. That's unusual for me."

The survey, conducted May 6-13, drew opinions from 1,003 travelers who made at least one roundtrip in the past 12 months.

Allan Rivlin, a partner at Peter D. Hart Research Associates, one of the two research firms that did the survey, said travelers were most critical about aspects of the air travel experience that are beyond airlines' control, such as the airport security clearance process, and flight delays caused by the antiquated and overburdened air traffic control system.