With no driver to lean out of the windows and yell "get out of the way", Google's autonomous cars will have to be creative when it comes to dealing with pedestrians.

A patent filed by the web giant has revealed how its self-driving cars might alert those on foot about whether it's safe to cross the road in front of it, Digital Spy reports citing the Washington Post.

One of the methods outlined involves the use of loudspeakers on the hull of the car, sounding out warning messages if it is unsafe to cross.

The document also mentions electronic signage on the body of the vehicles to display messages broadcasting their current intentions.

Google has already begun early road testing on its driverless cars, but it is expected to be at least several years before you can legally own one.

The search engine firm isn't the only company exploring self-driving vehicles, with virtually every automaker scrambling to be the first to launch a fully autonomous vehicle.