Virginia is now looking for developers to buy or lease the air over two sites on I-66: The Rosslyn Metro station and the Metro parking lot at East Falls Church in Arlington County.
That means the development would be built over the existing highway, parking lot and train tracks.
Tony Kinn, from Virginia's Office of Public-Private Partnership, says the potential is substantial.
"It could be residential, it could be mixed use," he says. "I can tell you this, it's gonna be a showpiece."
Kinn says there are other potential sites in Virginia where the air rights could be sold, including over Metro's new Silver Line tracks and stations in Fairfax County.
The money raised from either selling or leasing the air would go to both the state and local governments for transportation.
Similar leases in Massachusetts brought in $40 million in 2011, with a potential $868 million over the life of the lease.
The Arlington County projects now being showcased for potential developers could also include park land and bike trails.
Pat Herrity, Fairfax County supervisor, says he requested the state look into the possibility of selling air rights over the Dulles Toll Road.
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