Google's self-driving cars project has been slowly upping its efforts, as the prototype cars have been hitting San Francisco's roads with greater regularity. They have, however, hit a few snags, getting into altercations with cyclists, as well as driving too slowly for police. As such, this newly discovered patent makes for some interesting reading. Originally found by The Washington Post, the patent would retrofit current prototype vehicles to communicate with other drivers and pedestrians respectively. 

This new patent would essentially allow the self-driving cars to 'talk' with others on the road with a series of lights and signs placed across the car. In the image below, the self-driving car could, for example, flash a sign alerting pedestrians that it's safe to cross. Added to this, is the idea of a robotic hand, considering self-driving cars have no other physical gestures to communicate with other drivers. To that end, it could signal vehicles behind it that it's safe to pass, should the car be driving too slow for their liking. 

While all this remains concept at this stage, it's clear that Google has no plans to slow down the self-driving car project.