Driverless cars are becoming more common in some California cities, but when the autonomous vehicles violate traffic laws, police haven't been able to ticket them - until now.

The state's Department of Motor Vehicles (DMV) has announced new regulations on autonomous vehicles (AVs), including a process for police to issue a "notice of AV noncompliance" directly to the car's manufacturer.

The new rules, which will go into effect 1 July, are part of a larger 2024 law that imposed deeper regulation on the technology.

There have been a number of reports of the cars breaking traffic laws, including during a San Francisco blackout last year.

The California DMV is calling the new rules "the most comprehensive AV regulations in the nation".