A few months ago we reported that Google had joined the autonomous car world by announcing its own prototype. According to the Associated Press, automakers have been testing their skills on California roads for years. With the latest addition from the Google fleet the Department of Motor Vehicles couldn’t figure out how many self-driven vehicles were on the road.

To formally regulate testing the Department of Motor Vehicles is now requiring that self-driven cars be registered and issued testing permits. This new regulation will allow three companies to dispatch 29 vehicles onto freeways and into neighborhoods with a human behind the wheel in case there is an error made by the vehicle.

Google’s fleet consists of 25 Lexus SUVs making it the largest. Mercedes-Benz and Volkswagen of America have two vehicles each, said Bernard Soriano, the DMV official overseeing the state's "autonomous vehicle" regulation-writing process. A "handful" of other companies are applying for permits, he said.

California's DMV is currently drafting regulations that will govern self-driving cars once they are ready for the general public. Those regulations will address issues such as whether a person needs to be in the vehicle and are scheduled to be completed by the end of the year.