It would take an act of Congress to privatize rest areas along Interstate 81 in Virginia. Or at least a waiver.

Virginia Department of Transportation spokesman Jeff Caldwell said federal law prevents the state from charging travelers for goods or services at rest areas along the federal interstate systems.

Other states, like West Virginia, have gotten around the law by locating commercialized rest areas along toll roads. Others were grandfathered in before the federal ban was passed.

Privatization is one alternative being considered since the agency recently proposed closing 25 of the state's 41 rest stops, including most along the 325 miles of I-81. The department anticipates the move would save $12 million.