The California Department of Motor Vehicles has granted Waymo the state's first permit to test autonomous vehicles on public roads without a safety operator in the driver's seat.

Alphabet-backed Waymo launched its first driverless vehicle test program in Phoenix last year. 

The DMV's permit allows test vehicles to operate day and night on city streets, rural roads, and highways with speed limits of 65 mph. Vehicles are equipped to safely drive in fog and light rain. If a vehicle encounters a situation it doesn't understand, the vehicle will stop and contact Waymo fleet and rider support on how to proceed. 

Waymo's test vehicles are restricted to parts of Mountain View, Los Altos, Sunnyvale, Los Altos Hills, and Palo Alto, in Northern California. 

"We will gradually begin driverless testing on city streets in a limited territory and, over time, expand the area that we drive in as we gain confidence and experience to expand," company executives wrote in a blog post on Medium. 

Waymo hopes to launch an autonomous ride-hailing service in Phoenix by the end of the year, in addition to expanding its California testing grounds in the Bay Area.