Arlington County residents who say their lives would be grievously affected by an expansion of Interstate 66 are prepared to fight a proposal made last week by Virginia Gov. James S. Gilmore III (R) to add two lanes to the congested roadway inside the Capital Beltway.

"There would be major ramifications throughout our neighborhoods, environmental and social," said Mary McCutcheon, president of the North Highlands Civic Association. The interstate cuts a path straight through the North Arlington community, and McCutcheon said homes, parkland and recreational paths would be directly affected by an expansion of the road. "I feel very betrayed, and I can speak for the rest of the neighborhood when I say that if the discussions go further, we'll be ready to fight it."

Four months ago, Rep. Frank R. Wolf (R-Va.) stirred heated debate in Arlington when he called on state officials to study adding a third westbound lane to I-66. If another lane were added, Arlington officials said, it would violate a 22-year-old federal promise to limit the highway to two lanes each way.

But Gilmore's proposal has taken the idea even further, asking state officials not only to study a westbound lane but to consider the addition of a third eastbound lane.

The idea stunned many residents, who said Gilmore's proposal lacked careful consideration of alternatives to ease congestion on I-66. They criticized the suggestion that the road might be widened before residents directly affected could be consulted.

"It's unfortunate this [proposal] is out there without anyone having talked to the community first," said Gerry Procanick, immediate past president of the Bluemont Civic Association, whose community is also divided by I-66.

"Before people start making a quick judgment, we need to look at all the facts," he said. "I'm not quite certain what the government is trying to accomplish. . . . Traffic is a concern, but the reality is that as soon as you put the other lane [onto I-66], it's going to be a parking lot just as it is today. Is that a wise expenditure of funds? I'm not sure that is."

Procanick said other, less-costly alternatives to widening the road, such as the addition of more parking at the Vienna Metro station and the use of shoulder lanes on I-66 during rush hour, should be considered.

"What's the long-term plan here?" Procanick asked, adding that widening the road seems more like a short-term solution. "It doesn't seem particularly innovative."

Arlington County Board member Chris Zimmerman (D) agreed, saying Gilmore may be ignoring better alternatives, such as stricter enforcement of car-pool limits during rush hour, when the road is restricted to car pools eastbound in the morning and westbound in the afternoon.

Gilmore also has proposed extending rail lines to Tysons Corner, the area around Dulles International Airport and Centreville. Zimmerman said the effect of those potential additions should be considered before money is spent to expand I-66.

And even if the 1977 federal agreement with Arlington to limit the highway's width is put aside, Zimmerman said, the county is still left with the significant logistical and structural problems of widening I-66 "that suggest to me it wouldn't be cost-effective to begin with."

"People aren't real happy with the governor in Richmond making a decision for people in Arlington when no one has contacted anyone in Arlington," Zimmerman said. "That's driving a lot of the reaction. . . . I get the sense this hasn't been entirely thought through."

Ellen Bozman, who sat on the Arlington County Board for 24 years before retiring in 1997, agreed, saying residents' unhappiness is being driven largely by two things: They don't think additional lanes will help solve the traffic problem on I-66, and they feel betrayed by officials who promised that the road would remain as it is.

"I know that conditions change, but there's still a flavor of promises made, promises kept," Bozman said. Even if residents were to lay aside their feelings of anger, Bozman said, the proposal to widen I-66 doesn't make sense.

"You come back to the question of, are these roads, which cut through neighborhoods, going to be the way we can make real progress on our transportation problem?" Bozman said. "I'm not willing to say anything can solve it, but we should be looking to those items that can have the greatest impact. I don't think you can say that about another lane on 66."