To the company that wants to buy and develop it, the northeast corner of the Capital Beltway and Rte. 50 in Fairfax County could be a commercial gold mine worth more than a quarter of a billion dollars.

It could also be, the company says, an innovative model for transportation policy in the 1980s, a job center that actually proposes to penalize solo commuters and reward those who use car and van pools and mass transit.

"This is a gem, an incredibly great tract," Herbert S. Miller, president of Western Development Corp., says of the 158-acre property, the last undeveloped parcel of prime commercial real estate left along the entire length of the Beltway. "It may be the finest office location in the Washington area."

Miller's company is so eager to develop the land it has proposed an extraordinary array of blandishments to keep the 4,000 to 5,000 workers who would commute to and from the site from choking the area with cars.

It is not unusual for developers, in an effort to get the zoning they want, to throw in some transportation improvements. But generally the improvements are built around the automobile.

No developer in the metropolitan area, according to observers, has gone so far as to actually discourage automobile travel and get employes into vans and car pools and mass transit -- and to tie the success of his project to those efforts.

But despite the company's claims, Fairlake, as Western has dubbed its project, is in serious trouble.

Shrewdly orchestrated citizen opposition, most of it aimed at the Fairfax County Board of Sueprvisors (six of whom are seeking reelection), could seal off Western's gold mine, which eventually would include two office buildings and a 500-room hotel around a 21-acre lake.

It could also, company president Miller says, kill what he terms his company's good-faith effort to create the "environmentally sound development" that Fairfax Board Chairman John F. Herrity (R) has made one of the themes of his reelection campaign.

Today, the supervisors are scheduled to vote on Western's request to have the property rezoned for commercial development.

The citizens of surrounding areas say that if Western gets what it wants their neighborhoods will be choked with traffic and pollution. Route 50, already heavily laden with cars and trucks, will be jammed from the Beltway to Fairfax Circle, about three miles, during the morning and evening rush hours, the citizens claim.

That won't happen, Miller insists.

To ensure that it won't, Western, in an 11th-hour move, has agreed to:

Subsidize vans, special long-distance bus routes and Metro shuttles to the future Dunn Loring rail station a mile away to encourage workers to leave the cars at home.

Charge for parking and locate peak rush-hour places farthest from the building.

Stagger work hours.

Hire a full-time transportation coordinator to make all these schemes work.

Make more than $6 million in road improvements, including an overpass that would carry eastbound traffic nonstop from Rte. 50 to Fairlake, on the other side of the road.

Limit initial construction to only a quarter of the square footage ultimately sought.If Fairlake's traffic from the southbound Beltway lanes exceeds 650 cars per peak period, Western could not add one brick to Fairlake.

If all these efforts failed, Western would do more, Miller says. It would pay all the costs of vans used by commuters and subsidize Metro fares of others.

Furthermore, Miller says, all these promises would be put in a legally binding agreement.

"What else can we do?" asks Miller.

The concessions put Western close to what the county staff recommended in their own 11th-hour maneuvering.

But the neighborhoods, organized in a politically potent coalition called SCORE (Support and Conserve Our Residential Environment), have not been persuaded by what one leader called "last minute" concessions that are too late to study before today's board action.

"There are no substantive revisions to warrant a change in our position," said another leader, Joanne Malone, president of the Pine Spring Civic Association, after a Friday night meeting with SCORE's leaders.

But there are some chinks in SCORE's anti-Fairlake stand. At the Friday night meeting, an effort to get the group to drop its outright opposition and recommend withdrawal of the rezoning application (which would permit six to eight months' study of the new concessions before a new hearing) nearly succeeded.

Fairfax Supervisor James M. Scott (D-Providence), in whose district Fairlake would be built, has carefully stayed in SCORE's slipstream.

If he accepts SCORE's latest position, he probably would recommend that Western's application, despite the concessions, be denied. That could lead to the collapse of the Fairlake proposal -- or a court suit brought by Western or the present owners, the eight heirs of the Chiles family, which at one time owned all the land that the Beltway-Rte. 50 interchange straddles.

Western's Miller, whose firm is also heavily involved in Georgetown's redevelopment, insists all the traffic controls would work -- and says there is ample evidence from other job centers from California to New Jersey.

To buttress his claims for Fairlake, Miller cites a letter from a top federal Environmental Protection Agency official that praised the company's plan as an "excellent example" of traffic control and a "good model of major employment centers."

But the constituencies of the Board of Supervisors do not include EPA. They are angry residents who are genuinely concerned that Fairlake will overwhelm them with traffic -- residents who, when they get well organized, can be the deciding factor in the generally light voting for candidates for the board.

As SCORE spokesman George Cahlou said, "Western's people are very smart, very knowledgeable, and it's very difficult in this county to go against heavy citizen opposition."