Three state senators toured Honolulu International Airport yesterday to inspect a taxicab levy system that many taxi drivers and others complain is inefficient.

The system functions on dual tracks: an open method, run by Ampco System Parking, in which taxi drivers pay $4 each time they arrive and then wait on a first come, first served basis for passengers; and a pre-arranged method, run by the state, in which taxi drivers and other transport providers pay a $100 annual registration fee and a 7 percent levy on each fare.

The state's method, part of a $1.4 million contract, requires drivers to have transponders on their vehicles to record their activity at the airport.

The problem, the senators found, is that the transponder concept has never worked properly since it started nine years ago.

Sidney Hayakawa, with the state, said drivers pay the 7 percent levy off gross monthly receipts under an honor system, with the idea that the accuracy of their payments could be checked against computer records of their activity. But there is no indication the payments are routinely audited for accuracy.

The initial vendor of the transponder system has gone out of business, and the state has a new vendor that has brought in new equipment that will undergo testing after April.

Asked whether the state could be losing money because of the honor system, Hayakawa said, "Hard to say. How are you going to verify that?"

Taxi drivers in both the open and prearranged methods complain about waiting times and rules that prevent them from providing more efficient and friendly customer service.

Some drivers also say rogue competitors often poach fares because they rarely get caught and penalized.

The senators — Donna Mercado Kim, D-14th (Halawa, Moanalua, Kamehameha Heights); Michelle Kidani, D-17th (Mililani, Waipi'o); and Clarence Nishihara, D-18th (Waipahu, Crestview, Pearl City) — suggest that perhaps a single system would be more efficient.

The senators support a resolution calling for a management audit of the state Department of Transportation.

Kim said the airport taxi issue deserves attention.

"They're the first point of welcoming, and the tourists are inconvenienced, the drivers and the taxis are not happy because of the inconvenience that they have, so we have a situation that's volatile and is not helping us as far as the aloha spirit and portraying this hospitality that Hawai'i is supposed to be known for," Kim said.