LOS ANGELES — California’s Department of Motor Vehicles will miss a year-end deadline to adopt new rules for cars of the future because regulators first have to figure out how they’ll know whether “driverless” vehicles are safe.

It’s a rare case of the law getting ahead of an emerging technology and reflects regulators’ struggle to balance consumer protection with innovation.

Safety is a chief selling point, since self-driving cars – thanks to an array of sensors – promise to have much greater road awareness and quicker reaction time than people. Plus, they won’t text, drink or doze off.

Though the cars are at least a few years away from showrooms, seven companies are testing prototypes on California’s roads, and regulators have questions: Do they obey all traffic laws? What if their computers freeze? Can they smoothly hand control back to human drivers?

DMV officials say they won’t let the public get self-driving cars until someone can certify that they don’t pose an undue risk. The problem is that the technology remains so new there are no accepted standards to verify its safety. Absent standards, certifying safety would be like grading a test without an answer key.

Broadly, the department has three options: It could follow the current U.S. system, in which manufacturers self-certify their vehicles; it could opt for a European system, in which independent companies verify safety; or the state could (implausibly) get into the testing business.

“It’s a huge undertaking,” said Bernard Soriano, who oversees the DMV’s regulatory process. “There are all of these issues that need to be adequately answered.”

Manufacturers generally would prefer self-certification. That may be where California ends up, but for now the DMV is exploring independent certification – something that doesn’t exist for driverless cars.

In July, the DMV asked third-party testers whether they’d be interested in getting into the game. The department doesn’t have the expertise to create a safety standard and testing framework, so “the department wanted to get a very good sense of what is out there in the market,” according to Russia Chavis, a deputy secretary at the California State Transportation Agency, which oversees the DMV and requested a deeper exploration of third-party alternatives to self-certification.