Self-Driving Cars

Imagine a 600-mile trip from Denver to Kansas City in the year 2030. For most of the journey, your car cruises at 80 mph, unassisted and in complete safety. You're in the driver's seat, but the car does the driving.

The self-driving car isn't a new idea. "General Motors showed cars following magnetic strips as far back as the 1939 New York World's Fair," notes Chuck Thorpe, director of the Robotics Institute at Carnegie Mellon University in Pittsburgh. But attention is shifting to vision systems in which two or more in-car video cameras watch pavement markings and other highway features.

Already, Minnesota has a pilot program that helps snowplows stay safely on the road in blizzard conditions. Forklifts scoot around warehouses unassisted, following magnetic floor stripes or triangulating their positions via video cameras or laser scanners against wall markings. And next year, the Defense Advanced Research Projects Agency will sponsor a 300-mile off-road race from Los Angeles to Las Vegas for "autonomous robotic ground vehicles." The fastest finisher earns $1 million.

All are a far cry from future self-driving passenger cars and trucks that travel long distances safely at high speeds. Yet while autonomous driving lies over the 25-year horizon, the technological building blocks are coming together now as assistive aids.

"They won't drive for you," says GM vice chairman Bob Lutz of the coming decade's vehicles, "but they'll keep you safer." If you are rounding a curve in a car that knows exactly where it is, "the system in the car would postpone an incoming [cellular] call for a few seconds," says Gonzalo Bustillos, a director in Microsoft's Automotive Business Unit.

Global-positioning receivers and digitized maps exist today, but they will need to be more accurate. And barely a handful of cars currently have electronically controlled throttles and brakes. An inertial sensor (an electronic gyroscope accurate to within a couple of inches) would be needed when the car is in a tunnel or if a camera is temporarily blinded.

On highways, a car has just a 3-foot margin of error before it drifts off the road or out of a lane, so multiple redundancy is needed, says Thorpe. Cameras would provide lane departure warnings (via a gentle rumble in the steering wheel). Other cameras (or sonar, laser, or radar) arranged to face backward could warn you not to change lanes.

Meanwhile, the FCC has allocated spectrum at 5.9 GHz for an 802.11a-style dedicated short-range communications (DSRC) network for cars. It would initially be used for toll collection and measuring traffic congestion. Later, says Daniel Dailey, an engineering professor at the University of Washington, "One car could tell another that there's a collision five cars ahead, so slow down." Stop signs and traffic lights could also be fitted with DSRC transmitters.

Even if it is technically possible, will the self-driving car ever arrive? Most researchers envision self-driving cars within our lifetime to be mostly for limited-access roads. The technical issues may be solved before we have a handle on legal issues (who's liable in an accident), public acceptance (will taxpayers balk at funding lanes usable by just a handful of cars?), and emotional issues.

"People have their passions for driving. They may not want to be driven," says Akhtar Jameel, president and CEO of DaimlerChrysler Research and Technology for North America.

Most say it's hard to pin down when self-driving vehicles might become reality. The University of Washington's Dailey says it shouldn't be calculated in years but in engineering cycles, currently about three years from concept to production. His estimate: "I would guess it would be about ten car cycles before you see anything resembling autonomous driving." Good news, if you're passionate about driving.