The 3rd Grand Challenge competition will be held on November 3, 2007. DARPA will award prizes for the top three autonomous ground vehicles that compete in a final event where they must safely complete a 60 mile urban area course in fewer than six hours. First prize is $2 million, second prize is $500,000 and third prize is $250,000.
To succeed, vehicles must autonomously obey traffic laws while merging into moving traffic, navigating traffic circles, negotiating busy intersections and avoiding obstacles. DARPA will hold an Urban Challenge Participants Conference, May 20, 2006, in Reston, Va. At the conference, DARPA will review all aspects of the program, including application and proposal processes, schedule, rules, and technical goals.
More details in this DARPA announcement (pdf).