California has allowed limited use of its roads for automated vehicle testing in past years. But the state legislature, led by Sen. Alex Padilla, passed legislation that Gov. Jerry Brown signed in 2012 to establish new guidelines for testing and eventually consumer use of technologies.

The new regulations require proof of insurance or surety bonds for manufacturers testing automated driving research cars, and permits for company-designated operators of those vehicles.

Audi was the first firm to gain a permit from the state, saying that California roads are especially crucial to Audi Piloted driving testing because the state is home to the brand’s Electronics Research Lab. 

‘Audi is a driving force behind the research taking automated driving from science fiction to pre-production readiness,’ said Scott Keogh, president, Audi of America. ‘Obtaining the first permit issued by the State of California shows that we intend to remain the leader in this vital technology frontier.’

Meanwhile Mercedes-Benz has also received a licence permitting it to test vehicles in autonomous driving mode in daily traffic on California's roads, with the carmaker adding that this represents a further expansion of the company's extensive research activities in the USA.

‘With the approval from the US federal state of California we can now take autonomous driving to a new level in the USA,’ said Prof Thomas Weber, member of the board of management of Daimler AG responsible for Group Research and Mercedes-Benz Cars Development.

‘Through our new research activities we aim to promote the topic specifically in the USA, as the traffic system in the USA differs from the system in Germany in numerous aspects. The knowledge that Mercedes-Benz gains will help to achieve significant strides in the further technological development of autonomous driving,’ added Mr Weber.

The Associated Press has also reported that Google has been granted a permit by the state.