WASHINGTON - November 29, 2010 - With commercial airliners more crowded and heightened security measures threatening long delays at airports, private charter jet companies and rental car agencies may be beneficiaries of the growing airport headaches.

A Zogby International poll released last week found that 42% of likely voters said that enhanced pat-down search techniques and the increased use of full-body scanners by the Transportation Security Administration would cause them to use a different mode of transportation.

The trade groups that represent private charter jets and rental car businesses say the switch has already begun.

Demand for charter jets is up 52% so far in November over the same period last year, said Joe Leader, president of the Air Taxi-Air Charter Assn., a trade group for charter jet companies.

"The majority of that can be credited to an increase in business travel and economic recovery, but the TSA security hassle factor has absolutely had an additive effect on air taxi and air charter demand," he said.

Meanwhile, the American Car Rental Assn. reported an increase of 6% to 11% in rental business so far in November over the same period last year, an improvement that association Executive Director Sharon Faulkner attributes partly to the growing hassles of air travel.

You can blame the airport headaches on a rebounding economy and new security threats.

As the economy has begun to pick up steam, business travelers and vacationers who stayed close to home during the depths of the recession have begun to fly again, but airlines have resisted adding planes to accommodate the growth.

As a result, airlines are packing their cabins as close to capacity as possible. In August, the nation's airlines flew at 85.3% of capacity, the highest percentage for any August ever, according to the U.S. Bureau of Transportation Statistics.