The controversial final 10-mile section of Interstate Rte. 66 from the Capital Beltway to the Theodore Roosevelt Bridge opened for rush-hour traffic yesterday, but carried only a relatively sparse number of Northern Virginia commuters to Washington.

Only 893 car pools and van pools used the Washington-bound lanes of the new $275 million highway between 7 a.m. and 8 a.m., normally the busiest hour of the morning rush. The traffic was far less than the 3,000 vehicles that transportation officials estimate the two lanes could accommodate in one hour without a traffic jam.

Highway officials attributed the light traffic to the newness of the road, its four-member car pool restriction during rush hours and a seasonal drop in commuters as the Christmas holidays approach. "You can't declare it a success or a failure based on one day's operation -- or even on six months' operation," said Donald E. Keith, Northern Virginia administrator of the state Department of Highways and Transportation.

The sparse traffic was viewed by Rep. Frank R. Wolf (R-Va.) as further evidence that the car pool requirements should be relaxed, an aide said. Wolf, who represents the area and rode in a car pool on I-66, previously urged a shift to three-member car pools.

Virginia state and Arlington police, heavily patrolling the new highway, reported issuing $45 tickets to 18 drivers during the morning rush hours for failing to comply with rush-hour requirements restricting the highway to car pools and buses. State police said they also issued two summonses for speeding violations.

The road's opening -- after more than 20 years of court battles, shifting government policies and controversy -- was greeted by a mixture of delight, chagrin, confusion and uncertainty among motorists, government officials and residents of Arlington neighborhoods overlooking the road, officially named the Custis Memorial Parkway.

"That was fantastic," said Joseph Payne, a communications management specialist for the U.S. Customs Service, who rode to work on I-66 in a six-member car pool. "This trip was just so fast and furious." By switching to I-66, Payne said his group cut its travel time from Centreville in Fairfax County to D.C. by at least 15 minutes.

Several homeowners who live beside the highway said that noise and pollution proved less troublesome than they had feared. But they expressed concern that problems would mount as traffic increased. They also are worried, they said, that traffic noises and fumes may prevent them from opening windows in spring and summer.

"I was sorry to see it happen. It took some gorgeous, beautiful trees and lovely homes," said Harriet Foxwell, whose Stafford Street home overlooks the highway. "I don't know how it will be when summertime comes."

Some motorcyclists objected to being barred from the highway during rush hours. Nick Carrera, an arms control employe at the State Department, waited until the morning rush-hour restrictions ended at 9 a.m. before commuting to work. He said the highway shortened his trip by 10 minutes. But Carrera complained that normally he would have to get to work earlier and would be unable to use I-66.

Virginia highway officials were flooded with telephone calls from motorists, confused by the car-pool restrictions, entrance and exit locations and other questions. At midafternoon, officials reversed an earlier statement and announced that the rush-hour restrictions would not be enforced Friday or Dec. 31 because of Christmas and New Year holidays.