The Loudoun County Board of Supervisors has voted 5-4 to fund the Metro's Silver Line.
At issue was whether the county would kick in $270 million to extend Metrorail service past Washington Dulles International Airport, plus another $10 million in annual operating costs.
"A yes vote is for the future," said Ashburn District Supervisor Ralph Buona on Tuesday.
Three members of the public spoke at the meeting before the vote, with all three saying they favored the expansion.
Supporters of the Silver Line expansion have said it would reduce traffic and bring jobs to the county, while others -- including four board members -- were outspoken against it, due to the cost.
Catoctin District Supervisor Geary Higgin said prior to Tuesday's vote that he would not support the package, arguing that the federal government and Dulles Airport needed to pay more.
If the board had voted not to fund Phase 2 of the Silver Line project, the two planned stations in Loudoun County would have been dropped from plans.
Former Virginia Gov. Tim Kaine, who's now running for Senate, released a statement that reads in part: "I believe in the positive economic benefit of infrastructure investments, especially as we look for ways to strengthen our economy, create jobs, and put people to work."