COLOURFUL ceremonies on November 17 marked the start of construction on San Diego’s $431m Mission Valley East light rail extension. The 9·5 km route will connect the Mission San Diego terminus of the Misson Valley West route to the Orange (El Cajon) line in La Mesa.

This is the most expensive light rail extension since the Trolley network opened in 1981, primarily because it includes a 1·6 km tunnel and deep-level station below the University campus. Several design changes have recently been made to lower costs, including a slight shift in the tunnel alignment to allow the use of cut-and-cover construction. In addition, several bridges have been eliminated.

The new line is scheduled for completion during 2004. The four new stations, at Grantville, San Diego State University, Alvarado Hospital Medical Center, and 70th Street, are expected to generate 10800 extra trips per day by 2015. n