Morning commuters on Central Park’s West Drive met fewer bumper-to-bumper hassles yesterday due to the barring of single-occupant vehicles by the city, observers said.

The city’s Transportation and Parks & Recreation departments put into effect yesterday a high-occupancy-vehicle rule along the West Drive, between the Lenox Avenue entrance and the Seventh Avenue exit, during the morning peak period. The initiative, which is part of a series of steps to increase recreational use of Central Park and decrease its vehicle congestion, helped whittle down traffic to levels near those of country roads.

“I would say the numbers were down by at least 70%,” said a limousine driver with Carey International, R. John. “It was an easy drive this morning.”

In addition to requiring drivers to have at least one other passenger, the city agencies also reinstituted the holiday traffic plan, which closes the drives to traffic on weekdays between 10 a.m. and 3 p.m. and between 7 and 10 p.m.

Yesterday, from 7 to 10 a.m., Parks and Transportation officials informed motorists of the occupancy rule as they sought entrance to the drive. While only some motorists were turned away, the park was clearly more welcoming to morning joggers, dog-walkers and bicyclists, said the president of the Central Park Conservancy, Douglas Blonsky.

“It’s hard to tell after a holiday weekend and the first day of a program, but traffic volume was definitely down and was running smoothly,” Mr. Blonsky said, based on his own observations and those of several members of his staff in the field yesterday.

The HOV restriction on the West Drive may become permanent if the traffic remains consistently low, said a transportation department spokeswoman, Kay Sarlin. That has occurred on the upper deck of the Queensborough Bridge, which also has a morning occupancy restriction.

In addition to that initiative, the city is limiting traffic to Central Park by closing five access points and allowing cars in only seven hours a day. The city closed entrances and exits to the park yesterday at West 90th Street, West 77th Street, the West 72nd Street “slip off ramp” to Strawberry Fields, East 90th Street and East 102nd Street.

Starting January 3,cars no longer will be permitted on the drives from dusk to dawn, and the midday weekday closings will remain in effect. That should do even more to enhance the recreational value of the park, said a campaign coordinator for Transportation Alternatives, Kit Hodge. The nonprofit group campaigns for increasing the use of transportation other than cars in the city.

“Even if traffic is sometimes light in the park, it can be scary for pedestrians dealing with cars coming up from behind them,” Ms. Hodge said.

City officials said once all the initiatives are in place, traffic flow will decrease by about 25%. But while they expressed optimism over the first day of their plan, they are reluctant to draw conclusions until concrete traffic patterns develop over the next few weeks, Ms. Sarlin said. A carriage driver, John Sheridan, said he hopes the volume of cars in the park will decline to a trickle, giving his horse the room it deserves.

“I really would prefer no traffic in the park,” Mr. Sheridan said. “It’s not a street, it should be quiet and relaxing.”