Traffic is seen beneath a track for the new Silver Line in Tysons Corner in this 2012 file photo. (Jeffrey MacMillan/JEFFREY MACMILLAN)

The Fairfax County Board of Supervisors is set to decide Tuesday whether to raise real estate taxes in Tysons Corner to help pay for billions of dollars in transportation improvements as the county works to transform the area into a new, vibrant downtown.

Supervisors were slated to vote on the issue in December but delayed action after a long public hearing at which dozens of residents angrily criticized the tax increase as unfair. The biggest sticking point has been whether to include homeowners or exempt them.

As proposed, the new tax district would generate $250 million over the next four decades. When members of the county’s planning commission first suggested it as part of a much larger plan for financing billions in Tysons transportation improvements, they recommended trying to exclude homeowners, who make up only a small percentage of Tysons landowners. By fall, though, county officials had decided to do away with the exemption, saying they believed state law would ultimately prevent them from legally limiting the tax to commercial landowners.

Supervisors were widely expected to approve an across-the-board tax hike last month. But after the public hearing, they again reversed course, saying they wanted to try to work with the state’s General Assembly on legislation that would allow for the residential exemption.

The decision to postpone the vote renewed hope among homeowners that they might be excluded after all, but so far there are no guarantees. On Monday, Sharon Bulova (D), chairman of the board, said the county is still working to try to come up with a solution. She said she is hopeful that the tax hike will pass on Tuesday and that a means of sparing residents will soon follow.

For years, Fairfax has been working on plans to remake Tysons from a sprawling, traffic-clogged office park into a walkable urban center where people live, work and play. The effort culminated with the adoption of an ambitious master plan in 2010, which calls for the area to be largely rebuilt over several decades around four Metro Silver Line stations that will open later this year.

In recent months, the county has begun taking tangible steps to implement the master plan, including figuring out how to fund more than $2 billion in transportation improvements — public-transit projects, sidewalks, bike lanes, a new grid of streets and a handful of major roads — that planners see as essential for the new Tysons’ success.

Supervisors endorsed a funding plan last year that calls for developers to bear most of the costs, but it also suggests contributions from existing landowners, in the form of the tax district.

An exact rate — probably between 7 and 9 cents per $100 of assessed value — would be set when the county adopts a budget in April. Landowners would begin paying in July.

While the county has justified the tax district by saying all Tysons landowners stand to benefit from the area’s redevelopment, many residents disagree. They argue that the county’s plan for Tysons, at least in the near term, will only mean more construction, traffic and noise for the people who live there.

Residents have called it highly speculative to suggest that all property values in Tysons will increase, and they have said that if the county’s goal is to draw more residents to the so-called “edge city,” the tax district will do just the opposite.

Many also have criticized the district’s proposed boundaries as too wide. In addition to state legislation that would allow for a residential exemption, Bulova said the county is exploring changes to the law that would allow for a tiered tax rate, so that landowners closer to the heart of Tysons would pay more than those on the periphery.

About 18,000 people live in Tysons, and 100,000 work there. The county’s master plan envisions a city that will be home to 100,000 residents and 200,000 workers by 2050.