Senator Alex Padilla of California and California Gov. Jerry Brown arrive in a driverless car before a signing ceremony for SB 1298 at Google Headquarters in Mountain View, California on Tuesday, September 25, 2012. Photo: Gary Reyes/San Jose Mercury News/MCT

Waymo, the robotic car company created by Google, is poised to attempt a major technological leap in California, where its vehicles will hit the roads without a human on hand to take control in emergencies.

The state Department of Motor Vehicles on Tuesday cleared Waymo's driverless cars to cruise through California at speeds up to 65 mph. To start, the fully autonomous cars will give rides only to Waymo's employees and confine their routes to roads in its hometown of Mountain View and four neighboring Silicon Valley cities — Sunnyvale, Los Altos, Los Altos Hills and Palo Alto.

The self-driving cars have traveled millions of miles on the state's roads since Waymo began as a secretive project within Google nearly a decade ago. But a backup driver had been required to be behind the wheel until new regulations in April set the stage for the transition to true autonomy.

Waymo is the first among dozens of companies testing self-driving cars in California to persuade state regulators its technology is safe enough to permit them on the roads without a safety driver in them. An engineer still must monitor the fully autonomous cars from a remote location and be able to steer and stop the vehicles if something goes wrong.

California, however, won't be the first state to have Waymo's fully autonomous cars on its streets. Waymo has been giving rides to a group of volunteer passengers in Arizona in driverless cars since last year. It has pledged to deploy its fleet of fully autonomous vans in Arizona in a ride-hailing service open to all comers in the Phoenix area by the end of this year.

But California has a much larger population and far more congestion than Arizona, making it an even more challenging place for robotic cars to get around. If all goes well, Waymo will then seek volunteers who want to be transported in fully autonomous vehicles, similar to its early rider program in Arizona. That then could lead to a ride-hailing service like the one Waymo envisions in Arizona.

But Waymo's critics are not convinced there is enough evidence that the fully autonomous cars can be trusted to be driving through neighborhoods without humans behind the wheel. “This will allow Waymo to test its robotic cars using people as human guinea pigs,” said John Simpson, privacy and technology project director for Consumer Watchdog.

Those concerns escalated in March after a fatal collision involving a self-driving car being tested by the leading ride-hailing service, Uber. In that incident, a self-driving car with a human safety driver struck and killed a pedestrian crossing a darkened street in a Phoenix suburb.

Waymo's cars with safety drivers have been involved in dozens of accidents in California, but those have mostly been fender benders at low speeds. All told, Waymo says, its self-driving cars have collectively logged more than 10 million miles in 25 cities in a few states while in autonomous mode, although most of those trips have occurred with safety drivers.

Distributed by Tribune News Service.