If New York City's experience is any guide, closing Washington's Rock Creek Park to cars during non-rush hours and on weekends would have little impact on traffic while encouraging greater public use of the park. h

New York City's top transportation planner, appearing on a panel discussion here, said that despite dour predictions, the closing of Central Park to cars had no noticeable effect on city traffic.

"People also said it would be impossible to take away a lane of traffic (to create a permanent bike-jogger lane in parts of both Central and Prospect Parks). But it's worked fine," said Samuel Schwartz, assistant commissioner of transportaion. "I think you'll find people who use Rock Creek Park can easily use other streets."

The District's top transportation official, Thomas M. Downs, agreed. But he warned, as he has before, that proposed traffic changes in the park should be made slowly.

The two men appeared on a panel at D.C. Red Cross headquarters, 2025 E. Street NW, to discuss New York City's experience in returning the historic Central Park and Brooklyn's Prospect Park to pedestrians, bicyclists and horse-drawn carriages.

Rock Creek Park Superintendent James Redmond, also on the panel, said the National Park Service will put off any decisin on traffic changes until next spring or summer. That will allow time for a traffic study on how the changes would affect District and suburban Maryland commuters. Additional public meetings will be held after the Park Service makes a decision, he said.

This spring, the Park Service held a series of public meetings on nine possible traffic "alternatives," including closing various sections of Beach Drive north of the National Zoo, reserving one of the road's two lanes for bicycles and joggers, and building a separate bike trail.

The closing of New York's Central Park to cars, except during weekday rush hours, was gradual, starting in 1966 when Mayor John V. Lindsay announced he was "giving the park back to the peopel."

At first, the park was closed to cars on occasional weekends. That was followed in 1967 by regular weekend closings and in 1968 by some weeknight closings.

Each year there was a new change extending the hours the park was closed to cars, Schwartz said. Now Central and Prospect Parks are closed to cars from Friday night to Monday morning and on weekdays from 10 a.m. to 3 p.m. and 7 to 10 p.m.

The changes proposed for Rock Creek Park, one of the oldest urban parks in American and one of th earliest federal parks, are modest by comparison.

Downs said the Park Service might consider full weekend closings -- one section of Beach Drive is now closed regularly on Sundays -- followed by "off-peak closures" on weekdays and then probably the elimination of one lane of Beach Drive on a permanent basis.

"You've got to build gradually," Downs said, to give motorists time to change their habits and the public time to return to the park.

Schwartz said use of both Central and Prospect Parks has increased substantially because of the auto restrictions.

The panel was organized by the People's Alliance for Rock Creek Park, a group of 19 environmental, bicycling, hiking and jogging groups. The alliance has proposed its own alternative: closing four short sections of upper Rock Creek Park to cars, but still allowing cross-park traffic and auto access to virtually all picnic areas. The Park Service has agreed to consider the proposal.