No matter how good a driver you might think you are, you’re bound to bump into something as time goes on. This seems to be the case for Google’s self-driving cars too, which it has been revealed have been in 11 accidents thus far. The good news is that they were all minor, and according to Google, these weren’t the cars’ fault. In an article published on Backchannel, Google goes into further detail about the lessons learned from the project thus far.

11 minor accidents (light damage, no injuries) seems like a pretty good rate, considering that Google pegs the amount of kilos driven by their vehicles at 2.73 million over a period of 6 years (autonomous and with a safety driver behind the wheel).

The majority of the accidents (seven) were caused by cars rear-ending the vehicles, while there were also side-swipes and a collision due to a car rolling through a stop sign. A review process allows Google to learn from each accident, while the company notes that they are starting to identify driver behaviour, such as lane-drifting and red-light running, that might point to a significant collision about to happen.

Chris Urmson, director of Google’s self-driving car programme, writes that, “Even when our software and sensors can detect a sticky situation and take action earlier and faster than an alert human driver, sometimes we won’t be able to overcome the realities of speed and distance; sometimes we’ll get hit just waiting for a light to change.” He goes on to talk about the type of behaviour noticed by the safety drivers of the cars, with more than a few regular drivers spotted reading books, and another playing trumpet while driving.

Urmson ended by stating, “We’ll continue to drive thousands of miles so we can all better understand the all too common incidents that cause many of us to dislike day to day driving — and we’ll continue to work hard on developing a self-driving car that can shoulder this burden for us.”