Two of the entries covered about seven miles of the roughly 150-mile course while eight failed to make it to the one-mile mark. Others crashed seconds after starting.
The race ended just before 11 a.m. after the final four competitors were disabled, said Col. Jose Negron, race program manager. Competitors suffered a variety of problems that included stuck brakes, broken axles, rollovers and malfunctioning satellite navigation equipment.
One six-wheeled robot built by a Louisiana team was disqualified after it became entangled in barbed wire.
"It's a tough challenge, it's a grand challenge - you can always bet that it's not doable. But if you don't push the limits, you can't learn," said Ensco Inc. engineer Venkatesh Vasudevan, shortly after his company's entry rolled onto its side several hundred yards from the starting gate.
The Pentagon's research and development agency planned to award $1 million to the first team whose microcircuit-and-sensor-studded vehicle could cover the roughly 150-mile course in less than 10 hours.
The Defense Advanced Research Projects Agency was sponsoring the Grand Challenge to foster development of autonomous vehicles that could be used in combat. Defense officials foresee using the driverless, remote control-free robots to ferry supplies in war zones.