A Waymo self-driving vehicle. https://waymo.com/ontheroad/ The California Department of Motor Vehicles just proposed a revised set of regulations that will allow self-driving cars to operate without a driver behind the wheel.

The proposal is a big win for automakers and tech companies that have been pushing for the more lenient regulations. California proposed draft regulations in Dec. 2015 that required a driver to remain behind the wheel, resulting in pushback from Google's self-driving unit and others.

The release of the revised regulations on Wednesday marks the start of a 15-day comment period from the public. The DMV will then submit the new rules to the state government to start enforcing them in 2018.

Forty-two companies currently have a permit to test autonomous vehicles in California.

"We are excited to take the next step in furthering the development of this potentially life-saving technology in California," California Transportation Secretary Brian Kelly said in a press release.

Companies must comply with federal safety standards and certify that their vehicles are designed to follow state traffic laws, per the new set of regulations. They must also provide advanced notice about tests and disengagements, which is when a car stops operating autonomously while driving.

On the federal level, the House of Representatives in September unanimously approved the Self Drive Act, which would allow automakers to deploy 25,000 self-driving cars in the first year, a number that would rise to 100,000 over a three-year time span.

The bill still has to secure a vote in the Senate, though it appears on track to pass. The National Highway Traffic and Safety Administration would have to write permanent rules for self-driving vehicles as part of the bill.

Advocacy group Consumer Watchdog has called for the California DMV to disallow self-driving vehicles to operate without a driver behind the wheel until NHTSA passes enforceable standards for the cars.

"The new California DMV proposal wrongly relies on the federal government, when there are absolutely no Federal Motor Vehicle Safety Standards applying specifically to autonomous vehicle technology," John Simpson, Consumer Watchdog’s Privacy Project director, said in a press release.