The bill, authored by State Senator Alex Padilla (D-Van Nuys), was passed by the state Assembly on Wednesday and then given the overwhelming thumbs up by the state Senate the following day.
If signed by Governor Jerry Brown, Padilla's bill would legally allow autonomous vehicles on the road and charge the state's Department of Motor Vehicles with determining the standards for self-driving cars, rules which current do not exist under the present vehicle code.
The Economist notes that about 90 percent of traffic accidents are caused by human error, meaning that if humans are taken out of the process, there's a strong probably that accident rates will plummet.
Even so, the bill requires the cars to have a flesh-and-blood human being behind the wheel if something goes wrong.
"It sounds space age, but it's almost here," Padilla told the San Jose Mercury News. "If we can reduce the number of accidents, that alone is worth doing this bill."
Bay Area tech giant Google has been leading the way in self-driving cars. The team behind the project asserts that the technology is largely already there and their self-driving cars are ready to hit the road right now.
Earlier this year, Google took a number of state legislators on a test non-drive of their driverless cars.
"I had the pleasure of going out for a drive on the autonomous vehicle," California state Senator Alan Lowenthal told Reuters. "I have to say that there are some still issues with it, but it's a better driver than I am."
Earlier this week, Google engineers announced that their fleet of self-driving cars have logged a combined total of 300,000 miles.
Despite the bill's widespread political support, some quarters have voiced reservations, particularly over what happens if driverless cars crash and lawsuits are filed. "This does not protect adequately the manufacturers for liability concerns," Alliance of Automobile Manufacturers spokesman Dan Gage told the Mercury News.
California is the second state to pass legislation addressing self-driving cars; Nevada passed a law last year. In May, Nevada's DMV issued the country's first license plate to one of Google's self-driving Priuses.
Hawaii, Florida, Arizona and Oklahoma are all also considering similar legislation.