Valley Metro will build an 11-mile extension of its light-rail network from downtown Phoenix after last week's approval of the project by the Maricopa County Association of Governments.
The project is expected to cost $1 billion. About half of the project will be financed through a county sales tax devoted to transportation, with the other funding expected to come from the federal government.
The new western segment, which will serve the state capitol complex, is expected to be completed by 2023.
Design and engineering work can begin when the project gets environmental clearance. Current plans call for five stations along the western extension.
Valley Metro chief executive Steve Banta said the route design will provide opportunities for economic development and community revitalization.
"It will help ease congestion on the busy Interstate 10 freeway and provide swift connectivity to jobs, schools, activity centers and entertainment options across the valley," Banta said.
Phoenix Mayor Greg Stanton said the light-rail system is important to the city's future. "It creates jobs, further connects our community with sustainable transportation options and creates a multitude of new business development opportunities," he said.
The first 20-mile segment of the light-rail system opened in December 2008. It served 13.2 million riders in 2011.
Valley Metro expects to operate a six-segment, 57-mile network in the Phoenix area by 2032. Work began in early July on a three-mile segment in into downtown Mesa.