A Human Driver Vs. Robby The Autonomous Racecar

It’s a sunny morning at Sonoma Raceway, north of San Francisco—a great day for a race. My driver, Robby, pulls up to greet me. Robby is not a person. It’s a car—an autonomous racecar, to be precise—and it’s ready for a fight. Outwardly, Robby is an Audi RS7 sport sedan, bright red and tarted up with black racing stripes and a giant logo. On the inside, however, it contains some of the most sophisticated autonomous-driving equipment—cameras, laser scanners, accelerometers, precision GPS receivers, microprocessors—on the planet.

As I stand there, helmet in hand, admiring the machine idling in the pit lane, Klaus Verweyen, head of Audi’s piloted-driving development program, explains how the ride will go. First Robby will take me on a few hot laps around Sonoma’s 2.5-mile circuit, home to many NASCAR and IndyCar races. Then I’ll hop into a conventional—i.e., nonautonomous—model to try to beat that time. It’s man versus machine, a John Henry-like battle for the postmodern age.

The ride is aggressive but clean, fast but not furious.

As I slide into the passenger seat, I’m greeted by a young engineer named Markus Hoffmann. He’s been with the same Audi program for several years, but today his only job is to hold a kill switch that will instantly return Robby to human control if it tries anything suspicious. Besides that, he’ll just enjoy the ride. I buckle up and tighten my chin strap. Then Hoffman pushes the button on the center console, and we take off down the front straight like a cannon shot. We scream through 60 mph, then 80, then 90. Turn One arrives quickly, and Robby grinds the brakes down to a perfect entry speed. The steering wheel snaps smartly to the left. At the apex, Robby throttles up and spins the wheel back in the opposite direction, carrying us smoothly out and onto the next turn.

I quickly see that Robby is very, very good at this. The ride is aggressive but clean, fast but not furious. It’s a computer’s version of a professional race lap, with precisely modulated braking yet healthy doses of tire squeal in the turns. We fly through the esses, all the while maintaining a uniformly safe distance from the walls and low curbs.

In the future, autonomous cars will need to be like Robby, able to drive fast and react to quickly changing conditions and roadways. Robby allows engineers to test autonomous systems against strains many human drivers never consider: heavy braking, load-shifting under rapid steering, sudden changes in traction when you roll over grass or gravel. Robby’s driving style is also different than a human’s. “Human drivers will push a car to the physical limits and then dial it back if they get in trouble,” Verweyen says. “We start dialed back and then try to push harder.” Because of that, Robby will always be safer, at least in theory. Hoffman hasn’t had to hit that kill switch yet.

Compared with my digital adversary, my laps are sloppy and erratic.

After several laps, Hoffman takes control to ease us into the pit lane, a precaution because there are people around. Then it’s my turn. I get behind the wheel of a conventional RS7. I stomp the pedal to the floor. I’m not a racecar driver, but I’ve done my share of laps. Sonoma is tough—many turns, lots of elevation changes. Things happen quickly, and I struggle to keep up and make the right braking, steering, and throttle decisions at the right times. I realize I’m following Robby’s line based on my laps with him, but just a hair more poorly, just a tad slower. I think and guess, whereas Robby assesses and knows. Compared with novices, my driving looks clean enough, but compared with my digital adversary, my laps are sloppy and erratic. I even hop a few of the curbs that Robby knows to avoid.

When I finally cross the finish line, my time is 2:10. Robby’s is 2:02. Granted, a professional race driver familiar with the track could smoke us both; their average time is 1:55. But that’s going all out. As Verweyen said, Robby is dialed back.

It’s just a matter of time before robot cars rule both roads and track at any speed.

Want to see what the car of the future will look like? Check out the rest of our Car Disrupted feature here, from the November 2015 issue of Popular Science.