Phoenix, Ariz. - The state transportation board has authorized a consortium of private companies to negotiate a possible contract to build and operate up to $650 million worth of toll road facilities for the East Valley region of the metropolitan area.

The project, called MetroRoad, would add new toll express lanes on up to 46 miles of East Valley freeways and accelerate construction of up to 20 miles of the state's planned San Tan Freeway. Express lanes would begin opening by 1999, and the entire San Tan facility would open by 2004, eight years before the state has scheduled completion. MetroRoad would use electronic tolling technology to monitor road use, and patrons would pay a flat monthly fee for unlimited miles of use.

All tolls would cease on the San Tan mainline lanes by 2008 and on all express lanes by 2015, according to Bruce McKendry, vice president of Arizona-based HDR Project Services Corp., the project manager.

The project is the first to take advantage of a special 20-year sales tax passed by Maricopa County voters to fund construction of the Valley Regional Freeway System. Additional funding has been made available through the state's Transportation Project Privatization law.