A new airport shuttle will increase its fleet in the next few days to accommodate customer traffic from Cambridge to Logan Airport. And taxi drivers are not happy about it.

U.S. Shuttle, which made its first run just ten days ago, offers hourly pickups at Johnston Gate and two other locations for $8.

"We don't feel in competition with cabs," said Jim Wall, U.S. Shuttle's general manager.

Taxicab drivers in Harvard Square, however, say their business has suffered as significantly fewer passengers request airport service. Cabbies say Harvard students have virtually abandoned cabs, which can cost up to $25 a ride, in favor of the new shuttle.

Carlos Netzahuatl, a local taxi driver, said that before the shuttle service opened, he averaged six or seven trips a day. In the last ten days, his daily average has dropped to one.

Another Square cabby, Pierre Ripert, blamed U.S. Shuttle for a 50 percent reduction in his airport business over the past week.

Taxicab drivers are especially disgruntled because the shuttle service is not required to pay the $8,500 licensing fee for passenger pickup.

Last month, the City Council agreed to license U.S. Shuttle in Cambridge, ending a drawn-out legal battle between the fledgling company and local drivers.

Cabbies are still upset about the ruling, and complain of a double standard.

"They are doing a taxi job, but they are not a taxi," Ripert said.

But Wall defended his service, saying U.S. Shuttle appeals to a different market--and doesn't interfere with taxi drivers' business.

"These people use the T or friends, methods that cost less," he said of his customers.

Wall said he is optimistic about the company's future, expecting brisk business this weekend, as well as long term expansion.

He said he hopes to eventually add buses to his fleet of vans.