Driverless cars

The most incredible race in the world...without any drivers!

Read all about the wackiest race in the USA - where the only thing missing is a human behind the wheel. Eighty-nine unmanned vehicles start, six finish...

Auto Express Car Reviews

Meet Boss: a General Motors-backed Chevrolet Tahoe

By John Rettie

20th November 2007

It sounds like a recipe for disaster – driverless vehicles racing round an urban environment with other traffic on the road. And normally it would be if it wasn’t for the fact the unmanned cars had been developed by some of the world’s leading scientists and fitted with state-of-the art technology to prevent them crashing into anything.


	Considering the complexity of the course and the difficulty of the challenge, it was amazing how few incidents  there were. None of these would have caused injury

This is the DARPA Urban Challenge – an event for boffins and techno geeks, and one with a massive .5million up for grabs. Would the robotic cars go crazy and hit buildings, would they run amok and crash into motors driven by humans, and what would happen when one ’bot met another on the road?

To find out, Auto Express headed to an abandoned military base in Victorville, only 100 miles from Hollywood, California, to watch the action.

Before sunrise, the teams readied their cars. People from all over the world gathered in a tent to hear about the rules. Dr Norman Whitaker, the director of the race, reiterated that these were entirely autonomous vehicles. He said: “There is absolutely no communication between the car and humans.” Yet, despite this, the machines would have to navigate a complex 60-mile course which had 30 human-driven cars on it to simulate normal traffic.

But why do this? Several years ago, US Congress mandated that by 2015 a third of all vehicles on the battlefield have to be autonomous, unmanned drones. DARPA, the US Government’s Defense Advanced Research Projects Agency, which has jumpstarted several technologies including the Internet, was frustrated by the slow pace in robotics, so it came up with the idea to run a race.

The first event was the Grand Challenge in 2004. Sadly, it was a dismal failure as the furthest any machine managed on the 142-mile off-road desert course was seven miles.

DARPA organised another race in 2005, and offered a million prize fund to tempt the country’s best brains to take part. This went well, as four vehicles finished the 132-mile desert route. The winner was a VW Touareg nicknamed “Stanley” developed by Stanford University in California.

“The 2004 event was the equivalent to the Wright brothers flight at Kitty Hawk, where their plane didn’t fly very far, but showed what was possible,” DARPA director Dr Tony Tether explained.
“Today, the same is true for driverless vehicles.”

After the success of the 2004 event, DARPA came up with this year’s far-tougher Urban Challenge. This time, robotic cars would have to navigate a town environment, as well as other traffic and obstacles. They would have to obey all the rules in the California Driver’s manual, and complete three missions within six hours, while covering approximately 60 miles.

During the year, 89 teams submitted their vehicles for approval. After running trials, agency officials invited 35 of them to bring their ’bots to Victorville to perform qualifying runs. It wanted
to make sure they were safe.

The toughest qualifying test was where the unmanned machines had to drive around a two-lane course while making two left turns with random human-driven traffic coming from each direction. They had to stop and wait for a sufficient distance between vehicles to be able to pull out safely.

Each human had a kill-switch so they could remotely stop a ’bot in case it headed straight for them. By the end of the test, only one piloted car had been damaged, but several unmanned vehicles had touched barriers or run off the marked course. DARPA only allowed the 11 that completely the circuit without a hitch to go through to the final.

One key piece of technology that has been developed since the 2004 race is the Velodyne sensor. It appeared on top of most of the robotic cars, and uses 64 lasers that spin round to capture a
million data points a second. This allows the cars to see a distance of 200 yards, all-round, in 3D.

Many also used simpler sensors called ‘lidar’, which uses both laser and radar and provides close-up vision such as viewing lane markings and cars and pedestrians. All robots used GPS to position themselves on the correct road and point in the right direction.

Of course, all this sensor equipment is useless without some incredible artificial intelligence. That’s where the real skill comes in – programming a robot to decipher the info, understand it and then actually make decisions. “They have to be as smart as a person,” said Sebastian Thrun, Stanford University’s team leader.

On race day, officials uploaded details of the course each vehicle had to drive onto their on-board computers. With safety in mind, speed limits ranged from 10 to 40 mph.

Unsurprisingly, it was not long before there were a few mishaps, and the whole race had to be halted. Sadly the crowd’s favourite, Terramax, a giant 24-ton Oshkosh truck, was one of the first vehicles out when it decided to try to demolish a concrete column.

Another amazing scene was when a Subaru spent around 15 minutes stuck at a stop sign. Team Cornell’s Chevrolet Suburban came up behind and started to pass, before realising there was a stop sign and that it was on the wrong side of the road. Other ’bots arrived at the crossroads and correctly decided to go in other directions to avoid the jam. But one unmanned Toyota Prius (left) just took one look and, without hesitation, made it’s way through the gap past the confused Suburban. Everyone cheered!

The Massachusetts Institute of Technology’s Land Rover Discovery had the most computer power of all the entrants. But all this counted for nothing. The Disco finished the missions, but failed to win.

Just before the six hour-time limit was up, Stanford’s VW Passatt,“Junior”, crossed the finish
line slightly ahead of Boss, a Chevy Tahoe built by Pittsburgh’s Carnegie Mellon University. Both had completed their missions successfully with no errors. However, the million first prize went Boss. Junior took home million, while third place and 0,000 went to Virginia Tech’s Victor Tango team, which ran a Ford Escape hybrid. In total, six unmanned vehicles crossed the finish line.

Considering the complexity of the course and the difficulty of the challenge, it was amazing how few incidents there were. Even if emergency safety switches had not stopped wayward robots, there would have only been four accidents – and none of them would have caused serious injury.

“This competition has advanced our understanding of what is needed to make driverless vehicles a reality,” said Larry Burns, General Motors vice president of R&D and Strategic Planning, who helped back the Chevy Tahoe entrant. “Imagine being chauffeured in your car while eating breakfast and doing your E-mail. The technology in “Boss” is a stepping stone toward delivering this.”

It was fascinating to watch autonomous cars passing those driven by humans. Seeing them make decisions on how to go around parked vehicles was like looking into the future. Ironically, the human drivers were seen running stop signs and crossing lines. But then again, humans aren’t quite so obedient – especially when there’s no risk of getting a ticket!