The U.S. state of California has granted a permit to Alphabet's self-driving car unit to conduct fully driverless testing on public roads.

The unit, Waymo, said the permit issued by the California Department of Motor Vehicles (DMV) is the result of new DMV regulations that took effect in April, which allows companies to apply to fully test vehicles without a backup driver in the front seat on the state's public roads.

Waymo will conduct its driverless test cars in the neighborhoods of Mountain View, headquarters of its parent company Alphabet that also owns Google, and other areas including Sunnyvale, Los Altos, Los Altos Hills, and Palo Alto in Silicon Valley.

"We know this area well ... Mountain View is home to more than a dozen autonomous vehicle companies, and has supported safe testing for years," Waymo said on Tuesday.

Fully driverless testing is the latest step in Waymo's self-driving ambition since 2009, and it has since driven over 10 million autonomous miles on public roads across 25 cities.

California is the latest state added to Waymo's driverless testing program, which was launched in Phoenix, Arizona since last year, said the Silicon Valley-based autonomous car company.

With the permit, Waymo's driverless cars will be tested during daytime and at night on city streets, rural roads and highways with posted speed limits of up to 65 miles (about 104 km) per hour.

"Our vehicles can safely handle fog and light rain, and testing in those conditions is included in our permit," Waymo said.

Waymo plans to eventually roll out a self-driving car service for customers in California, and it is close to launching its first commercial taxi service in Phoenix, Arizona by the end of this year.

Earlier reports said the California DMV has licensed about 300 vehicles from 60 companies conducting driverless tests in the state.