Photos: Robot race in 'DARPA' city

The Defense Advanced Research Projects Agency (DARPA) raised the green flag Saturday on 11 driverless cars to drive a 10-plus mile course at the former George Air Force Base in Oro Grande, Calif., or what race officials called DARPA city. It's part of DARPA's $3.5 million robot race, the Urban Grand Challenge.

Tartan Racing, whose vehicle is pictured here at the start gate, was expected to leave the shoot first, but it had an expected technical problem, so it left the starting gate last. One of the Carnegie Mellon University team members said that it was having trouble pulling down positioning data from its GPS (global positioning system).