“A race car driver can use all of a car’s functionality to drive fast,” said Gerdes, a professor of mechanical engineering. “We want to access that same functionality to make driving safer.” By testing the physical limits of speeding cars, Stanford engineers hope to develop safer autonomous driving systems. When Stanford’s autonomous car Shelley nears speeds of 120 mph as it tears around a racetrack without a driver, observers’ natural inclinations are to exchange high-fives or simply mouth, “wow.” For the past several years, Gerdes and his students have been testing their autonomous driving algorithms with Shelley, a custom-rigged Audi TTS, on the 3-mile track at Thunderhill Raceway in Willows, California. Although the speedometer needle sometimes flies past 110 mph, the car spends a good deal of the course maneuvering at speeds of 50 to 75 mph. This is closer to the speed at which most car collisions occur, Gerdes said, and understanding how the car adjusts its throttle, brakes and makes use of all the friction of its tires in these situations could inform the development of automatic collision avoidance software.