http://googleblog.blogspot.com/2014/04/the-latest-chapter-for-self-driving-car.html The latest chapter for the self-driving car: mastering city street driving], googleblog In June 2015, the team announced that their vehicles had driven over 1000000 miles , stating that this was "the equivalent of 75 years of typical U.S. adult driving", and that in the process they had encountered 200,000 stop signs, 600,000 traffic lights, and 180 million other vehicles.