More commuters are riding buses and trains because of a Fairfax County experiment that lowered some rush-hour bus fares and raised parking fees at five Metro stations, according to a report released yesterday.

However, the county's six-month-old program has not eased the parking shortage at the five Metro stations, where the lots continue to fill before the end of the morning rush hour, the report shows.

The program began in March as an attempt to ease the parking shortage at the Vienna, Dunn Loring, West Falls Church and East Falls Church Orange Line stations and at the Huntington station on the Yellow Line. All the stations except East Falls Church are in Fairfax County, which proposed and is studying the one-year experiment. Arlington County agreed to include the East Falls Church station.

"We're happy about Metrorail ridership and we're very happy about bus ridership," said Andrew Szakos, Fairfax County's chief of transit operations, "but we wish the parking lots" did not fill so early in the day.

"No matter what we do with the buses, we're still going to need additional parking places," said Metro Board Chairman Joseph Alexander, a Fairfax County supervisor.

In the first six months of the program, rush-hour bus ridership has increased 56 percent on the bus routes feeding the Metro stations, an average daily increase of 3,000 passengers.

Morning rush-hour boardings on the rail system rose 13 percent.

All the parking lots fill by 8:40 a.m. At two stations -- Vienna and West Falls Church -- the parking lots are filling earlier than they did before the program went into effect.

The experiment, which included some additional bus service and an intensive marketing effort, "has done what it's supposed to do" by boosting bus and rail ridership, Alexander said. However, he said, "It's not going to take the place of additional parking places."