One of Google’s self-driving cars collided with a bus in Mountain View, California, last month.

The car was travelling at 2mph and pulled out in front of a public bus travelling at 15mph.

The Google car had a human inside who said he believed the bus would slow down to let the car out; this is why he did not override the vehicle’s self-driving computer.

Google self-driving car crashes into a public bus

In its monthly self-driving car project report, Google said: “This is a classic example of the negotiation that’s a normal part of driving – we’re all trying to predict each other’s movements. In this case, we clearly bear some responsibility, because if our car hadn’t moved there wouldn’t have been a collision. That said, our test driver believed the bus was going to slow or stop to allow us to merge into the traffic, and that there would be sufficient space to do that.

“We’ve now reviewed this incident (and thousands of variations on it) in our simulator in detail and made refinements to our software. Our cars will more deeply understand that buses and other large vehicles are less likely to yield to us than other types of vehicles, and we hope to handle situations like this more gracefully in the future.”