California has given the go-ahead to driverless cars after a governor signed state legislation allowing them onto public roads.
California governor Jerry Brown signed the bill by Democratic senator Alex Padilla, which will establish safety and performance regulations to test and operate autonomous vehicles on the state's roads and highways.
"We're looking at science fiction becoming tomorrow's reality – the self-driving car," Brown said, who rode to the signing ceremony at Google headquarters in the passenger seat of a vehicle that steered itself, a Prius modified by Google.
Google co-founder Sergey Brin and State Sen. Alex Padilla, who sponsored the bill, went along for the ride.
An engineer for the technology company, Chris Urmson, sat in the driver's seat, but the car drove itself.
"Anyone who gets inside a car and finds out the car is driving will be a little skittish but they'll get over it," Brown added.
Google has been developing autonomous car technology since 2010 and lobbying for the regulations.
The company's fleet of a dozen computer-controlled vehicles has logged more than 300,000 miles of self-driving without an accident, according to the Internet company.
"I think the self-driving car can really dramatically improve the quality of life for everyone," Google co-founder Brin said.
Autonomous cars can make roads safer, free commuters from the drudgery of driving, reduce congestion and provide transport to people who can't drive themselves, such as the blind, disabled, elderly and intoxicated, Brin said.
"I expect that self-driving cars will be far safer than human-driven cars," he said, adding that by driving closer together more safely than human-driven cars, self-driven cars might cut congestion.
He predicted that autonomous vehicles would be commercially available within a decade.
He said Google had no plans to produce its own cars, but instead wanted to partner the industry to develop autonomous vehicles.
But the Alliance of Automobile Manufacturers expressed concern that California was moving too quickly to embrace self-driving cars and needed to first sort out liability issues.
"Unfortunately this legislation lacks any provision protecting a car manufacturer whose car is converted to an autonomous operation vehicle without the consent or even knowledge of that auto manufacturer," the trade group said.
Google's autonomous cars use video cameras, computers, radar sensors, lasers and a database of information collected from manually driven cars to help navigation, according to the company.
However, a human driver can override the autopilot function and take control of the vehicle at any time.
With smartphone-wielding drivers more distracted than ever, backers say robotic vehicles have the potential to significantly reduce collisions and traffic fatalities, noting that nearly all car accidents are a result of human error.
The legislation requires the California Department of Motor Vehicles to draft regulations for autonomous cars by 1 January 2015.
Currently, state law does not mention self-driving cars because the technology is so new.
The new law goes into effect next year and establishes safety and performance regulations for testing driverless cars, provided a licensed driver sits behind the wheel to serve as a back-up operator in case of emergency.
However, it will likely take years before a fully self-driving autonomous vehicle hits the road, industry officials say.
Recently, carmakers have started incorporating into today's models some elements based on the innovations in those early vehicles, including adaptive cruise control or traffic-jam technologies that can slow the car automatically.
Carmakers developing autonomous technologies include BMW, Ford, General Motors, Honda, Hyundai, Mercedes, Nissan, Toyota, Volkswagen and Volvo, as well as suppliers, technology companies and universities.
Chip company Intel created a $100m fund in February to invest in future auto technology.
Nevada and Florida have already passed laws allowing self-driving cars.