Chris Gerdes, associate professor of mechanical engineering at Stanford University and director of the center for autonomous research at Stanford (CARS), describes testing of driverless 2009 Audi TTS at Thunderhill Raceway Park west of Willows on Thursday, June 28, 2012. The autonomous car made its way around the 15-turn, 3-mile track with a top speed of 120 miles per hour. Thursday's testing also included having David Vodden, president and CEO of Thunderhill, drive the racetrack while monitoring his brain waves. The research team will later analyze the data, comparing how a human reacts to driving the course versus the driverless robotic version.