People without access to cars needed an alternative to expensive taxi rides to get to Upper Marlboro, the Prince George's County seat, so the county launched a shuttle bus service about a year ago.

County officials had no idea how popular the service would be.

Now the buses -- actually blue vans -- linking Upper Marlboro with public transportation lines a dozen miles away are sometimes so full that riders are passed by along the route. Ridership has been so high and steady that the county has dropped the idea of operating the service on a "trial basis."

After the first six weeks of operation, the shuttle averaged 27 riders a day. After three months, 48 people a day paid the $1 fare for a one-way trip. Now, 81 persons, on the average, climb aboard the shuttle daily, said James Raszewski, chief of the transit division for the county Department of Public Works.

"The response has been phenomenal," he said. "We expected the shuttle to be used, but not quite like this. I think it is safe to say that as long as people keep using the service, we will keep it available."

Initially, Raszewski said, most riders who used the service were headed for hearings at the County Courthouse. Now, some county government workers use the bus to get to work. Others use the shuttle to get to stores in the Pen Mar Shopping Center.

The county tried a shuttle service once before, in 1974. But the service ended after a couple of months, because there were no riders, officials said.

The new shuttle van picks up passengers from the Landover and Addison Road Metrorail stations and in front of the Pen Mar Shopping Center on Donnell Drive in Forestville.

The service runs from 7 a.m. to 11 a.m. and 1 p.m. to 6 p.m. Monday through Friday