Google has been at the forefront of driverless car technology since its self-driving car project was announced in 2009.
In April 2014, Google announced it had logged over one million kilometres driven in autonomous cars in the US. It's also been responsible for lobbying US state governments to pass laws allowing Google to test its cars on their roads. So far, California, Nevada, Florida and Michigan have passed such laws.
Google's first full prototype was revealed in December last year. Google says the network of steering, breaking and sensor technology will allow it to launch a car that doesn't require a steering wheel or pedals.