Audi, BMW and Volkswagen also are jumping on the self-driven bandwagon. Audi's test model recently raced hands-free to the top of Colorado's twisty Pike's Peak.
Though the Google car is not street legal by itself -- the permit requires two humans inside and a $1 million to $3 million bond for road tests -- the milestone marks one giant leap toward a driver's license for robot-kind.
We shouldn't be surprised. Computers have been slowly taking the wheel for decades, from cruise control, anti-lock braking systems and on-board diagnostics, or OBD, to such recent innovations as collision avoidance and self-parking systems.
Despite the deadly and destructive behavior of the HAL 9000 of "2001: A Space Odyssey" fame, the compelling argument for autonomous driving research always has been its potential to save lives. Human behavior is the No. 1 risk factor in all forms of transportation, contributing to 32,885 highway deaths and 2.24 million crash-related injuries in 2010, according to the National Highway Traffic Safety Administration. Traffic accidents kill 1.3 million people and injure 20 million to 50 million every year worldwide, according to the World Health Organization.
Robot cars don't drink and drive
"Autonomous driving is undeniably the future," says Rob Enderle, a technology analyst based in San Jose, Calif. "A machine doesn't get sleepy, it doesn't drink, it doesn't text. Even if it did, it is certainly capable of massively multitasking, so it would do things like communicate and entertain you while still driving the car."
Teller says three things ultimately will enable your robot car to drive better than you.
- Sensors: "Machine vision" radar can not only detect objects and flawlessly execute traffic maneuvers, it can "see" through snow, fog and driving rain without need of wipers or headlights.
- Reaction times: Machines can react faster than humans and breeze through intersections when connected via Wi-Fi to traffic signals and other autonomous cars around them.
- Improved dynamics models: Robotic drivers can better sense what the car will do under any condition or on any road surface.
"Their collision-avoidance maneuvers, high-performance steering, and acceleration and braking will eventually be on par with the very best human race car and stunt drivers, and in the long run be even better than humans," Teller says.
Enderle notes that mixing human drivers with autonomous ones could initially make the road to implementation a bit bumpy.
"The robotic systems will work much better if the other systems around them are also robotic because they can drive closer," he says. "I mean, you could eliminate traffic with these things. All you do is create a communications link between vehicles, and they could automatically space themselves for changing lanes and all the rest. But add one human driver in that mix, and all the cars would have to back off and give the human plenty of space."
Direct vehicle-to-vehicle, or V2V, communications will be a key hurdle to overcome. Although today's prototypes use GPS to navigate around an obstacle course or on the open road, it's not much good for changing lanes, following flagmen or detecting when a child runs into the street.
Cars that communicate
But once autonomous drivers can communicate with each other, Teller predicts that social pressure will do the rest.
"You'll have situations where a bunch of robotic cars pull up to an intersection with their drivers lounging in the back reading the paper or working on tablets when somebody drives up manually," he says. "The chauffeured passengers lean out their windows and say, 'Hey, idiot! Let your car drive! You're endangering all of us!"
Despite the safety advantages of robot cars, Teller admits software and sensor failures are inevitable.
"If the accident or fatality rate is half or a 10th of what it is when humans drive, you'd get over that tipping point. We have mechanical failures all the time right now, and you don't see people stop driving," he says. "But there's a sea change that has to happen to cross that psychological barrier to give over complete control of the vehicle to the vehicle itself."
Lower car insurance
Cheaper car insurance may provide one incentive. "At some point, you will pay higher premiums to drive your own car than to have the robot drive your car," Teller says.
Tom Baker, a professor of law and health services at the University of Pennsylvania, agrees, noting that medical liability is one of the costliest parts of a standard auto policy.
"Automobile insurers give discounts to people who have safety features on their car," he says. "The cost of the bodily injury liability component of your policy should go down because the chance that you're going to injure someone else is low. And if you're not driving the car, how can it be your fault?"
What impact will robot cars have on fuel economy?
"It's massive," Enderle says. "Since you don't really have to get to work (in order) to work, you could more easily work in your car in transit. Your car could become your mobile office, so it doesn't really matter if you rush or not and the car can pick an optimum speed for fuel efficiency. You would either eliminate rush-hour traffic or make it so that people don't really care. Not only could you get there more quickly, it wouldn't matter if you didn't."