There are more than 10,000 licensed taxis in the Washington area, and at certain moments most seem to be parked at National Airport.

Almost a third of all passengers arrive at National by cab, according to the Federal Aviation Administration, with 91 taxi companies from the District, Maryland and Virginia competing to serve them.

"I think it's fair to call the situation a mess," said James A. Wilding, who runs National for the FAA. "The airport is open to any cabdriver in the region."

FAA officials say 5,000 taxis are dispatched from National on a typical day. Last year, 1.75 million taxi drivers each paid their 50-cent toll to the FAA for the right to vie for a fare. Because of huge turnover in the industry, many drivers are new to the business and often are new to the Washington area.

"I got here last week on a business trip," said Ron Tollen, a Detroit marketing executive, "and I asked the guy to take me to the Capital Hilton. Instead, he took me to Capitol Hill."

Also, travelers and officials complain about traffic tie-ups caused by the waiting taxis. Because there is no adequate parking for taxis, drivers routinely spill onto Smith Boulevard, blocking one of the airport's few significant roadways, often threatening to run onto the northbound lane of the George Washington Memorial Parkway.

Like many proposals for change at National, an FAA plan to demolish two underused hangars to accommodate taxis has been simmering on the back burner for years without the funds to implement it.

The rules for taxis at National are unique -- and uniquely confusing -- primarily because the airport sits at the edge of three jurisdictions. A Virginia driver may legally take a traveler to any destination from National, but District and Maryland cabs may take people only to their respective localities, according to the FAA. Because of the restrictions, there are two taxi lines.

The system was designed as an incentive to drivers, so a cab bringing someone to the airport from Greenbelt, for example, would not have to drive an empty car back.

Another aspect of the District system prompts constant complaints from customers: Charges are unfair because the cabs are not metered.

"It is unfortunate, but if somebody stares at the Washington Monument too long they are looking for trouble," said Rich Griesbach, manager of commercial operations for the Metropolitan Washington Airports. "There should be a single system. A cab should be a cab."

FAA officials and airline industry representatives have said they would like to see only metered cabs at the airport, but several attempts to bring meters to D.C. cabs have failed.

"It's like a lot of things at the airport," said John Flowers, who until recently was in charge of the taxi dispatching system at National. "It's a political problem. Everyone knows there is a huge amount of overcharging. There is no question about it. Without meters it's hard to eliminate. There has to be a better way."

Many cities issue medallions or permits to a limited number of cabdrivers who are then allowed to work at the airport. But primarily because of the jurisdictional wrangles, that has not been done at National.

"It's what you call an open system," said Flowers. "That means anything goes."