Tucson Sun Link will run for 6.2km from Congress Street in Mercado to the city centre, University of Arizona, and Helen Street with 17 stations. The project includes the construction of a bridge over the Santa Cruz River at the western end of the line, and a depot near 9th Street station.
Services will operate at 10-minute intervals during the peak and every 20 minutes at other times.
The first LRVs are due to arrive early next year for testing and commercial services are set to start at the end of 2013.
The total cost of the project is $US 196.8m, including the fleet of seven vehicles and maintenance facilities.