This summer some of the self-driving cars will be tested on the roads around Mountain View, California, where the search giant is based.

Before now, the small vehicles have only driven on test tracks and have not mixed with regular traffic.

Google has tested autonomous vehicles on public roads but all of them have been heavily modified Lexus SUVs.

The robot cars will not be completely autonomous, but will have safety drivers on board who can take over if needed.

Source: BBC