U.S. Secretary of Transportation Ray LaHood on Thursday sided with Northern Virginia officials in proposing that the Metro station at Washington Dulles International Airport be built aboveground as part of an effort to trim about $1 billion from the rail project’s cost. The proposal ends a month of contentious meetings between the Metropolitan Washington Airports Authority, which is overseeing the construction project, and top officials in Fairfax and Loudoun counties, who, along with Dulles Toll Road users, will pay for it.

LaHood’s proposal is a blow to the airports authority, which has been insisting on building the Dulles Metro station underground even though it would cost $330 million more than the aboveground station that Loudoun and Fairfax favor.