A Metro board committee has sidestepped action on a plan to increase lighting while slashing costs in the transit system's dimly lit vaulted subway stations, but it decided to move ahead with an experiment to provide more light in aboveaground stations and parking lots.

In a spirited debate at a meeting Thursday, proponents of brighter, direct lights underground said the lights are 80 percent cheaper and considerby more safe than the soft, indirect lights the stations have now. But partisans of the existing lights, which bounce off walls and reflecting panels, said the lights enhance the stations' appearance and promote an atmosphere of "calmness and restfulness."

The architects who designed the stations complained in a letter that new lighting would be "disastrous to appearance."

After two hours of debate, the committee shelved the plan and asked its staff to study how to increase lighting on escalators, mezzanines and kiosks -- the dimmest parts of the stations.

For aboveground stations, which have lighting problems without accompanying aesthetic benefits, the committee agreed ona six-month experiement with brighter lighting at the Fort Totten station in Northeast Washington, D.C. City Councilman Jerry A. Moore (R-At-Large), said the station area was so poorly lit that "people are afraid to wait" for buses after getting off trains.

The committee also voted to put brighter sodium lamps into the light fixtures at the New Carrollton parking lot. The bright lights will get a three-month tryout before the transit authority decides whether additional light fixtures are needed.

As forecast earlier, a quarterly operating report distributed at the meeting showed a drop in Metro ridership for the first time since 1973. However, the report said higher fares and cost-saving measures would keep the transit deficit about as expected.

On the positive side, the report showed that bus drivers' overtime had been reduced 29 percent compared with the same period last year, and that bus revenues in March covered 51 percent of costs for the first time since June 1978.

However, the number of bus riders was dowm 4.7 million -- about 4 percent -- for the nine months from July 1 to March 31, and the number of rail passengers was virtually unchanged despite the extension of the Blue Line to Addison Road in Prince George's County. The report said the Addison Road trains are running far below capacity and may soon operate with fewer cars.