Opening the Dulles Access Road to car pools and van pools would not slow traffic on the highway, which is reserved for airport users and commuter buses, according to an analysis released yesterday by Rep. Frank R. Wolf (R-Va.).

But the promoters of Dulles International Airport continue to oppose Wolf's proposal to relax the road restrictions, fearing that increased traffic on the road will discourage travelers from using the airport.

"It's very important for the airport's future that travelers be able to get to and from the airport quickly," said Thomas G. Morr, president of the Washington Dulles Task force, a private group that promotes the airport.

Wolf asked the Metropolitan Washington Airports Authority, which leases and controls the federally owned access road, to consider opening it to car and van pools to ease congestion on the parallel toll road, where rush-hour commuters fume in stop-and-go frustration while watching airport users speed past on the access road's uncrowded lanes.

"The Dulles toll road is no longer adequate during rush-hour periods to serve the needs of businesses and residents," Wolf said in a recent letter to authority board Chairman Linwood Holton. Wolf said his proposal "would be of great assistance to citizens until the long-term solutions of additional lanes and mass transit are available."

A recent spot check of traffic on the access road by Wolf's staff found that it is operating at 27 percent of capacity, Wolf said in a letter last week to Holton. His staff counted 1,092 vehicles on the two eastbound lanes of the access road, from 7:30 to 8:30 a.m. Oct. 28. The staff estimated that the two lanes could handle 4,000 cars an hour without slowing traffic.

The staff counted 200 cars or vans carrying three or more passengers on the toll road during that same hour. Allowing those vehicles onto the access road would not slow traffic, the staff report said.

A traffic count during one hour of one day "doesn't strike one as a sufficient study," said Morr.

The airports authority has agreed to study Wolf's proposal, and is gathering information on access road use and on projected future traffic to the airport, said general manager James A. Wilding.