After nearly 20 years of protests, a Beltway exit onto a privately owned and maintained residential street, Kensington Parkway in North Chevy Chase, will be closed soon and covered with grass by the Maryland State Highway Administration.

The I-495 cloverleaf now carries about 9,000 cars a day from westbound lanes of the Beltway onto Kensington Parkway, where motorists then exit to Connecticut Avenue. The cloverleaf will be replaced with an exit directly onto Connecticut Avenue, where area residents insisted 20 years ago the exit should have been built.

A traffic light will be installed to enable motorists and trucks to turn left toward Washington. Beltway signs now prohibit trucks from using the Kensington Parkway exit. "But they do anyway and the police ignore it," says William Cookson, secretary-treasurer of North Chevy Chase Village.

The project, expected to cost $200,000 to $300,000, should be completed this fall, said to Tom Neukam, assistant area, construction engineer for the Maryland State Highway Administration.

Although the exit ramp will be closed, the state presently has no plans to close a ramp that leads from Kensington Parkway ont the Beltway.

Of the average 18,000 cars a day that use the three-lane parkway, 51 percent travel in the two southbound lands and 49 percent use the single northbound lane.

The majority of the parkway traffic -- 89 percent -- travels between Connecticut Avenue and the Beltway, according to county traffic officials. Less than 2,000 cars a day drive on Kensington North of the Beltway, where the parkway crosses Beach Drive.

The elimination of the Beltway exit, now less than 100 yards from Rock Creek, will return several acres of land to the Maryland-National Capital Park and Planning Commission.

The project, announced last spring, was delayed during a brief moratorium on more than a dozen major highway projects because of funding problems.

Kensington Parkway originally was two lanes, but was expanded to three and parking along it prohibited by the state when the Beltway was constructed in 1964. County traffic officials soon will have the option of making the parkway two lanes again and permit parking.

"The state offered to take over the street, said Cookson, "but they wanted to widen it to four lanes within a median strip which would have put the road and traffic right next to all the houses on the street."

The 181 houses in the North Chevy Chase Village special taxing district have paid for the upkeep of the parkway for nearly 20 years, said Cookson.

"We had no choice in the matter really. We fought it, but state officials said the Beltway traffic was coming through and there was nothing we could do about it," he said.

Residents along the parkway are still angry about the Beltway traffic.

"There's a constant roar from traffic along here, particularly from buses and trucks, although trucks are illegal on the road. It shakes everything in the house," Fendall Marbury, of 9010 Kensington Parkway said last spring.

The traffic is so heavy, said Anna Reeside, of 8910 Kensington Parkway, that, "I can never get out of my driveway before 9 a.m. because it's bumper to bumper cars in two lanes in front of my house, all the way to Connecticut Avenue. And even when I can get out I'm afraid to back out because it's on a curve and the cars go so fast, even through the speed limit's 25 miles an hour. I have to turn my car around on my front lawn, on the grass."

"The whole thing was somebody's screwy idea over in Baltimore," says Cookson. "Well believe it when the exit's gone. Now we'll start fighting to get the ramp onto the Beltway removed. The state says they'd have to take four houses in order to build a Connecticut Avenue ramp onto the Beltway that's baloney. They could do it without taking any houses. But will They?"