The development marks a milestone in the testing of autonomous automated vehicles.

In a significant development, California’s Department of Motor Vehicles stated, Alphabet Inc’s Waymo unit has been awarded a permit to test driverless vehicles without a backup driver in the front seat.

Waymo is the first company to receive such a permit from California’s Department of Motor Vehicles.

California has said, Waymo can use about three dozen test vehicles without drivers behind the wheel in Santa Clara County.

Incidentally, although most self-driving vehicles are designed to eliminate the need for a driver, testing for autonomous automated vehicles has so far been limited with a safety driver behind the wheel who can take over in case of emergency, new regulation adopted by California allows companies to test self-driving cars without a driver, on public roads with a special permit, from April 1, 2018.

As part of winning the approval from the Department of Motor Vehicles Waymo must continuously monitor the status of test vehicles and provide two-way communication with passengers, carry at least $5 million in insurance and notify local communities.

Its permit includes day and night testing on city streets, rural roads and highways with posted speed limits of up to 65 miles per hour (105 kph). Waymo said, its vehicles can safely handle fog and light rain, and testing in those conditions is allowed.

Waymo said, it will begin testing driverless vehicles in Silicon Valley and expand it to other areas after notifying local communities. At first, Waymo will first use its own employees in tests and eventually “create opportunities for members of the public to experience this technology, as we’ve done in Arizona with our early rider program.”

In Arizona, Waymo has been conducting some testing of vehicles without backup drivers and has said it plans to launch a commercial self-driving ride hailing service in the state by the end of 2018.

Last week, Ruth Porat, Alphabet’s Chief Financial Officer (CFO) said on an earnings call that customers were beginning to pay for rides in Arizona and the company was testing pricing models.

Significantly, California’s new law requires self-driving cars should allow a remote operator to take control of the vehicle if the underlying autonomous system inside the car encounters problems. Companies including Waymo, Nissan Motor Co and startups such as Starsky Robotics, Zoox, and Phantom Auto have been working on such technologies.