Audi, Google and Mercedes-Benz received permits from the state of California to test drive their cars on public highways.

New state regulations were enacted on Tuesday to allow the test for self-driving cars on public roads, based on a 2012 law signed by Gov. Jerry Brown. Google previously received a limited permit to test drive its self-driving cars because of the absence of a law allowing companies to do so, according to USA Today. The three companies are now allowed to test a total of 29 vehicles.

But, Audi considers itself as one of the leaders in the research about self-driving cars, as it was the first to receive the permit.

"Obtaining the first permit issued by the state of California shows that we intend to remain the leader in this vital technology frontier," president of Audi of America, Scott Keogh said in a press release.

Aside from California, other states including Florida, Nevada and Michigan also agreed to have carmakers test their self-driving cars on public roads. But Gov. Brown made sure that the state is ahead of all states in testing this emerging technology.

Audi has two self-driving cars at the Electronics Research Labs in Belmont, California and plans to bring two more for the test, according to Mashable.

The permit comes with strict regulations and guidelines for the vehicle, the car maker and the human driver testing the car. The automaker should have a $5 million bond to pay any claims of accidents, and the company should have a net worth of at least $5 million. The driver should have adequate training and the self-driving car should be tested in simulated environments before driving on public highways, Los Angeles Times reported.

In addition, the car should be registered first with the Department of Motor Vehicles (DMV) as a self-driving vehicle. When the self-driving system is deactivated, it should be able to switch and function as a regular vehicle.