RICHMOND, DEC. 7 -- The Governor's Transportation Commission and the Fairfax County Board of Supervisors took actions today designed to resolve problems that have stood in the way of a $392 million widening of traffic-choked Rte. 28 through Fairfax and Loudoun counties.

The county board, meeting in Fairfax, created a special tax district along Rte. 28 under which commercial property owners would be assessed to help pay for the road project. The Loudoun County Board of Supervisors deferred action on a similar proposal today, but is expected to approve the measure.

Meanwhile, the Governor's Commission on Transportation in the 21st Century, meeting for the last time here, recommended that the General Assembly approve the use of the money raised through those special assessments to pay off revenue bonds that would be sold to raise money for the project.

That idea would have to be approved by the General Assembly. Further, state officials said they need to determine whether the special tax district would generate enough money to finance the bonds. The issuance of revenue bonds would have to be approved by voters living within the boundaries of the tax district.

Widening Rte. 28 is considered critical to unraveling gridlock in the rapidly developing area around Dulles International Airport. State transportation officials had hoped to finance the project -- the most expensive projected for Northern Virginia -- through the use of so-called pledge bonds.

That method, which would have allowed the state to raise money by pledging gasoline taxes and other revenue to pay off the principal and interest, was declared unconstitutional last month by the Virginia Supreme Court.

The court, citing technical reasons in the state Constitution, said that use of revenue from such sources could not be pledged. That was a blow to the governor's commission, which had supported pledge bonds and was forced in recent days to come up with a new idea.

Revenue bonds, on the other hand, typically take money from a specific source, such as tolls, to retire a specific, clearly related debt. Tolls from the Dulles Toll Road, for example, finance revenue bonds sold to build that expressway.

State officials also had hoped for a favorable ruling on the pledge-bond issue but said today that the revenue bond proposal represents a realistic alternative.

"I don't know of any reason why it won't happen," State Finance Secretary Stuart W. Connock said in an interview. "I don't know of any downside risk. It's a very solid proposal."

Under the plan proposed today, the General Assembly would first authorize the use of bonds to finance the project. The bonds would be issued by the Commonwealth Transportation Board, which would then sign an agreement with a commission created to run the transportation tax district. Under that agreement, the commission would pay off the debt with the surtax on the affected real estate. First, of course, the bond issue would have to be approved in a referendum.

Government officials have estimated that about 80 percent of the improvements to Rte. 28 would be financed by nearby landowners through a surtax of up to 20 cents per $100 of assessed value.

In recent weeks, some landowners have expressed concern about the amount of money they may have to pay for the improvements and have sought to have a ceiling imposed on the surtax. The county says that the Board of Supervisors cannot impose a ceiling that would prevent another board from raising the rate in the future.

The resolution passed yesterday by the Fairfax board says simply that the board attaches "great weight" to the 80 percent estimate.

Curtis M. Coward, an attorney for the landowners along Rte. 28, said after the vote that the resolution went a long way toward resolving their concerns. "We're 98 to 98.5 percent there," he said. "We want a clear understanding we're going to operate this thing as a partnership."

The Loudoun board deferred action after developers raised objections to some of the precise language in the resolution, but agreed with Loudoun officials that the concerns were minor and essentially centered on a grammatical error. Staff writers John Ward Anderson and John F. Harris contributed to this report.