Several property owners along the Rte. 28 corridor, just east of Dulles International Airport, have agreed in principle to pay a surtax that would help finance the widening of Rte. 28, a project that is considered essential to support the expected development surge in that area.

The tentative agreement, worked out during a meeting this week with Fairfax County Board Chairman John F. Herrity, represents the first strong show of support by the property owners for a plan that Herrity has promoted as the best and fairest method of funding the improvements.

Eight developers owning nearly 2,000 acres of the approximately 5,000-acre corridor agreed to the concept and pledged to work toward persuading the remaining property owners to do the same, Herrity said in an interview. He called the action "a tremendous breakthrough" and added, "There's no question in my mind that, with this group making this commitment, the idea will fly."

All of the property owners contacted yesterday agreed that their companies, as primary users of the road network, should help defray the costs of major highway improvements.

"If we want this done any time in the next few years, everybody's going to have to give a little," said Victor Trapasso, president and chief executive officer of G.T. Investments, developers of the 2 million square-foot Renaissance Park just off Rte. 28.

Francis Steinbauer, senior vice president of the Henry Long Co., said it is "pretty clear to developers that there needs to be state, county and private participation" in the Rte. 28 project. The Henry Long Co. is developer of the proposed 1,048-acre Westfields project, which is one of the largest commercial ventures in Fairfax and is expected to attract 30,000 workers daily by the year 2000.

The Rte. 28 corridor is the focal point for some of the most ambitious commercial development plans in Northern Virginia, including the state's Center for Innovative Technology, which is expected to attract more high-technology business to the area.

Officials in Fairfax and Loudoun counties contend that driving conditions on Rte. 28, already a heavily congested highway, will become intolerable unless the two-lane highway now in place is expanded.

Herrity said he is prepared to ask the Board of Supervisors to request special legislation from the Virginia General Assembly to authorize the financing plan, which, if approved, would pay for the widening of Rte. 28 from two lanes to six between the Dulles Access Road and Rte. 50. Fairfax County officials have projected the cost at $50.5 million.

Fairfax County officials are trying to secure the developers' commitment to a surtax of up to 20 cents per $100 of assessed value to help fund the road expansion. The developers contacted yesterday said they are reluctant to agree to an additional tax of much more than 10 cents per $100.

"Conceptually we agree that this is a good idea, but we would like the tax to be as low as it can be so as not to place us at a disadvantage with other developers" in the Washington area, said Ray F. Smith, president of Webb-Sequoia Inc., developer of a proposed 3 million square-foot office park and three hotels at Rte. 28 and the Dulles Access Road.

Herrity, asked about the concerns expressed last year that homeowners in the vicinity of the corridor would be hit by the Rte. 28 costs, said that will not happen. "No residential property would be involved in this [financing plan] -- no way," he said.