Google revealed Monday that its self-driving cars have been in 11 minor traffic accidents since it began experimenting with the technology six years ago. The company released the number after The Associated Press reported that Google had notified California of three collisions involving its self-driving cars since September, when reporting all accidents became a legal requirement as part of the permits for the tests on public roads. The director of Google's self-driving car project wrote in a web post that all 11 accidents were minor "light damage, no injuries" and happened over 1.7 million miles (2.8 million kilometers) of testing, including nearly 1 million miles in self-driving mode.