In the worst crash yet of its self-driving cars that are currently being tested, a Google Lexus SUV a severely damaged passenger door where the impact occurred.
The accident did not result in any one being hospitalised,
Google said in its monthly reports outlining developments in its driver-less car project.
According to commentators, there was no doubt this particular incident would feature in Google's next report due for release at the end of this month.
In the meantime, Google issued a statement explaining how one of its Lexus SUVs was driving through Mountain View ''when a car heading westbound on El Camino Real ran a red light and collided with the right side of our vehicle.''
According to Google, the fault did not lie with the self-driving car.
Google added the road light was green ''for at least six seconds before our car entered the intersection,'' soon after which the other vehicle hit it.
Google noted, ''Thousands of crashes happen everyday on US roads, and red-light running is the leading cause of urban crashes in the US. Human error plays a role in 94 per cent of these crashes, which is why we're developing fully self-driving technology to make our roads safer.''
Although the outcome could have been much worse, the crash pointed to a key problem with the adoption of AV vehicle technology - that piloted and robotic vehicles would need to share the roads with vehicles driven by humans, for a long while.
While Google, Uber and others could design driverless systems that followed the law, but protecting against human drivers who were often reckless would be impossible. Crashes like the one that happened, would likely not disappear unless self-driving tech became the norm.