Cars That Drive Themselves

The Great Robot Race homepage

In the months leading up to the 2005 DARPA Grand Challenge, Sebastian Thrun, the head of Stanford University's Artificial Intelligence Lab, could not know whether his team's robotic vehicle, nicknamed Stanley, would triumph. Given the disheartening results of the 2004 Grand Challenge, in which no competitor had even made it through a quarter of the course, Thrun might well have been only cautiously optomistic. Yet when interviewed by NOVA producers Jason Spingarn-Koff and Joe Seamans, this robotics enthusiast was brimming with excitement, confident that the 2005 race would herald a new era of vehicles that drive themselves.

Dreamers wanted

NOVA: How sure are you that we'll be driving—or driven by—autonomous cars in the future?

Thrun: It's a no-brainer for me that at some point our cars will have the ability to drive themselves. Cars are young. They're just 120 years old, 100 years old, depending how you count. The car as a social phenomenon is maybe 80 years old. Just think 50 years ahead. There's no question that 50 years from now we'll have the technology for cars to drive themselves. In fact, I think we're amazingly close, and I believe this specific competition, the Grand Challenge, pushes us tremendously in that direction.

NOVA: Is that part of the thrill of the competition?

Thrun: I draw a lot of motivation from the dream that we all share here, which is to build cars that drive themselves. It's been fantastic to see a thousand people at the same location who all share this wonderful dream.

NOVA: How do you respond to critics who say it's impossible?

Thrun: There are always people who doubt the dreams, who have no imagination. I'm sure that the entire Industrial Revolution was a dream to people 500 years ago. Two hundred years ago, nobody would think that we'd plaster our country with pavement and filling stations to support a new infrastructure [for today's vehicles]. I prefer to spend my time with people who dream.

Maybe autonomous cars have failed so far. It's an idea that's 30, 40 years old. But the Grand Challenge should change that. Already, in test runs leading up to the race, vehicles have traveled hundreds of miles over unrehearsed terrain. That's never happened before. I think when people read the history of the automobile 100 years from now, this event will stand out as a really significant step towards making the dream a reality and communicating to people that we can actually do it.

NOVA: Why pursue the dream?

Thrun: Why is it needed? Well, we have 43,000 people die every year in traffic accidents in the U.S.; 6,000 in Germany, where I'm from. And they die mostly because of human error. If you build cars that drive themselves, eventually they'll be safer than human driving. And they'll free us from the burden of focusing on driving as opposed to being more productive while we commute.

NOVA: Is saving lives a big part of what inspires you?

Thrun: Yes. I lost a really good high school friend. He was in a car with another friend. They borrowed one of their parent's cars, and they took a turn too strong. They were 18 years old, hit a big truck head-on, and they were dead instantaneously. It was really tragic. And I wouldn't go so far as to say that Stanley [Stanford's robotic vehicle] could have assessed this and predicted this, but the type of technology that's being showcased in the Grand Challenge can actually anticipate something like this and interfere and say, "You know, you're going too fast." It can make people aware of dangers.

Maybe my friend would still be alive if the same thing happened 30 years later, because we will have cars that can detect these things at the onset. It's a very simple thing. Suppose the car realizes you're going too fast. The car could slow down, or it could just tip the brakes very briefly and the person wakes up and sees there's a threat coming up.

We humans usually feel that we are the best at everything we do, that we can safely drive ourselves. But tens of thousands of people die every year. We need to be open to having technology assist us, to find ways in which technology makes us safer.

A turning point

NOVA: Where does the vision of cars driving themselves come from?

Thrun: We've been surrounded by cars that drive themselves for a long time. Batman's car drives itself, you know, and we've kind of taken it for granted that it's going to happen in the real world. I've developed my passion for cars that drive themselves from being stuck in traffic for many, many, many hours of my life. I don't know what it adds up to, but I feel like I've lost a year or two just in traffic. That's big to me. That's a lot of time, a lot of money that I just lose on the road. And more importantly, as I've said, I've had friends who've lost their lives in accidents.

This is really a pivotal time. Up to now, we have had vehicles in which the intelligence is entirely provided by people and the horsepower is provided by the machine, and we're at the point where we can redefine this. We can say, "Let's also have the intelligence defined by the machine and make the device safer." In avionics it's happening already. There are aircraft that can be flown with computer control. In the automotive industry, it's the next logical step.

NOVA: What interests you most about the DARPA Grand Challenge? [DARPA is the U.S. government's Defense Advanced Research Projects Agency.]

Thrun: I think the Grand Challenge is ingenious. Tony Tether [the Director of DARPA] and DARPA are incredibly smart to do this. They threw out a goal that looked seemingly simple, but it's a huge step in terms of technology. If we can show that the principle is possible, then we'll have to make it more robust and so on. But in many things—the first air flight, the first telephone—the moment you show it's possible, it's just a matter of time until it's going to be a widespread reality.

NOVA: Are military applications an important motivation for you?

Thrun: I'm certainly not in it to build better ways of fighting wars, although I'm saddened by recent events, and if I can help to save lives, be it on the battlefield or not, I'd like to.

But I honestly believe the impact that we're going to make will go far beyond the military domain. Take another example from DARPA: DARPA created the Internet. The Internet was called ARPANET originally. It was for military people to talk to each other. Today the Internet has revolutionized the way people interact with each other in ways that are fundamentally different from even 10 years ago, and I think the same will happen with transportation.

“The day in the future when my car commutes for me—that will be the ultimate victory.”

I personally think cars that drive themselves will have their greatest impact in everyday life. For instance, for elderly people, typically when they stop driving, their social networks go away because they can't see their friends anymore. They can't go shopping. They become dependent. And it often correlates with physical deterioration. What if we give them a car that drives itself? Maybe they'd live longer. They'd certainly have a better quality of life. I think just looking at the military alone would not do justice to the many enthusiasts who want to make autonomous vehicles a reality.

NOVA: What technological advances are needed to make such vehicles a reality in everyday life?

Thrun: I honestly at this point don't really know, and I'd love to spend a year thinking about this when we analyze what actually has happened in the Grand Challenge. We've been busy just building the machine.

To make this technology a reality, you don't just drive two or three miles, you have to drive 20,000 miles without any accident, 50,000 miles, before people can even think about adopting it. And this kind of robustness really requires a fundamentally different understanding of the road surface. I think some of the steps have been taken for this Grand Challenge.

NOVA: What else is needed for widespread use of robotic vehicles?

Thrun: There are two big factors at this point. One is price. You have to scale down your platform from $40,000 to $2,000. That's just a matter of how much you produce. I think it's feasible. And the second is infrastructure. We have no structures right now to deal with autonomous cars. We have no special lanes on highways that say "For Autonomous Cars Only." We need a whole evolution of systems. We won't have autonomy tomorrow morning. We'll have a driver-assist system that helps a little bit to avoid obstacles, and then we'll go further, and at some point in the future, maybe 30 years from now, we'll have autonomous cars.

A pure machine race

NOVA: What's your main motivation for entering the competition?

Thrun: This is a fantastic scientific challenge. For me, it's not just about building Stanley; it's about understanding the nature of driving. We humans have much to learn about what it really entails to drive at high speeds safely. Preparing for this race, we already have made a number of fairly significant scientific discoveries, I believe, about how to perceive environments and how to drive that I think will have an impact beyond the Grand Challenge.

NOVA: Is the Grand Challenge an important historical event for robotics?

Thrun: I think this is a watershed moment of immeasurable magnitude. This is the first endurance race where the technology has to make all the decisions. It's not just about a component like running fast or thinking fast. It's about the integration of it all. The race is substantial. It's long. It's difficult. And every single decision is made by the things we've created, not by ourselves anymore. Humans—even though the teams are important—humans are out of the loop the moment the race starts. It's a pure machine race. And that, I think, is really new and unprecedented. The moment the race starts, we'll celebrate, we'll go to a bar and have a bottle of champagne, even though the race is still ongoing. When did that happen before?

NOVA: So it's different from other technology races in the past?

Thrun: Yeah. We've had a number of recent races—the circling of the globe in a balloon, for example, or going into deep space—that involved significant technology components. But in these races, it was always people who made the ultimate decisions. The Grand Challenge to me is entirely new. It's about the machine making every single decision. We have to build a machine that not just has the physical power to endure but also the brainpower to make all the decisions along the way. The machine becomes the actor itself. I think it's a fundamental step in the history of robotics, of humankind so to speak. I think this race will be heralded as an historical race.            .

NOVA: What will completing the course successfully mean for robotics?

Thrun: The implications of this race are much broader than some people understand. It's not just about building a car that drives a couple of miles. It's about replicating one aspect of human intelligence, in this case the ability to drive, to the point that the machine can do it entirely by itself. And there's no precedent for that in history.

NOVA: Who do you see as the main competition?

Thrun: You know, for me the competition is not against Carnegie Mellon or any other team. We're all in the same boat. The competition is to make the world's roads safer, and that's a competition that everybody in this contest is in together. Even if some other team wins, I think it's going to be a victory for the field. I'm going to be proud of having been part of the event. I'm going to be proud of DARPA for having pushed it. I think we lose if this year the best team does seven miles [the distance covered in the first DARPA Grand Challenge in 2004, in which no vehicle finished the course]. That would be a profound loss for us as a whole community of researchers.

NOVA: What would constitute a win for you?

Thrun: To finish the Grand Challenge and cash the $2 million check! But much more so, I think the race could push forward tremendous change in the automotive industry in terms of environment perception and driver-assistance systems that can make driving safer but still keep it pleasurable.

A couple of months ago, I spent about two hours every day commuting. The day in the future when my car commutes for me—and I can sit there, read the newspaper, do e-mail in the car while the car is driving itself—that will be the ultimate victory.