Arlington officials are maintaining a wait-and-see attitude and hoping for more use of the new Subway Shuttle Taxi, a service begun in November to supplement the Route 22 Metrobus line.

"Ridership has picked up," said Rick Taube, executive director of the Northern Virginia Transportation Commission.

The special taxi service was created in November so Arlington residents could use public transportation beyond the normal Metrobus schedule.

Route 22 runs from Ballston to Shirlington via George Mason Drive, Columbia Pike and Four Mile Run Drive.

The taxi service operates from 9 p.m. to 12:30 a.m. Monday through Friday and from 7:45 a.m. Saturday to 12:30 a.m. Sunday, picking up passengers every 20 minutes.

Transfers from Metrobus Route 16 are accepted by the taxi service at Metrobus stops along Columbia Pike between George Mason Drive and Four Mile Run Drive for riders traveling toward Shirlington or Ballston.

The fare is 80 cents, or 45 cents with a valid Metrobus or Metrorail transfer.

Residents within two blocks of the Metrobus Route 22 south of Columbia Pike can get pickup service with an hour's notice. They must be willing to wait at the curb for the cab and to share the ride if two or more riders are waiting at a pickup point, or if more than one request is received for the service.

Taube says the county's ridership and service expectations "have been met pretty well." He said ridership rose from 117 to 318 between November and January and added that the decision to continue or drop the service will be made in June, when funding from the Virginia Department of Highways and Transportation runs out.

Potential riders have been sought with a direct mail campaign and notices posted in Arlington. Taube compared the service to a similar operation in Alexandria, which is subsidized on a per-trip basis. "The Alexandria service carried more than 2,000 people last year, but it provides a more extensive service and serves the entire city of Alexandria," he said, noting that it picks up passengers whose origin or destination is a Metro station.

Arlington County Board member Ellen Bozman said the taxi service "is typical of new tries in transportation, in that they get off to a slower start than you might think. I certainly think we ought to keep trying new transportation alternatives. We can't afford to just let it lapse. We need to determine who's using it, and more importantly, who's not using it."

Taube said the Northern Virginia Transportation Commission was completing market research for the service by delivering surveys to residents of Falls Church and Centreville, which will be picked up on a Saturday in mid-March. Taube said such surveys get a higher response than telephone calls.

The Subway Shuttle Taxi is operated by the Arlington Yellow Cab Co. under a contract with the Northern Virginia Transportation Commission, and is approved by Arlington County with funding from the Virginia Department of Highways and Transportation. Yellow Cab keeps two drivers on duty and will dispatch an extra cab in the event of heavy use.

The drivers, who are allowed to keep passenger fares, bill the Transportation Commission for the number of hours worked. Arlington residents can get further information by calling 524-3322.