Google's self-driving car. Google Google has been granted a patent (via The Washington Post) that shows how its self-driving cars would communicate with pedestrians by using screens or a speaker system, potentially helping to avoid collisions.

The screens, which could be mounted on the doors or bonnet, would show signs such as "Stop," "Safe to cross," or a traffic sign, that would alert pedestrians to what the car is doing. This system is in place of a driver making eye contact or signalling to them.

The patent also outlines a speaker system that could communicate with pedestrians using alerts such as "coming through" or "safe to cross" if it is unclear who should go. There is also the suggestion of a robotic hand or eye that could make a pedestrian aware the car has "seen" them, according to The Post.

There are no sketches of how the system would work within the application, but it appears to be similar to a system Nissan showed off last month. Google applied for the patent in 2012.

Google recently announced that its self-driving cars had logged 100,000 miles on the open road with no accidents caused by it.