California motor vehicle department officials on Wednesday proposed self-driving car regulations that included mandating that a person could take the wheel if needed.

The draft set of rules released by the California Department of Motor Vehicles for a public comment phase would not allow for legal operation of an autonomous car being tested by Google because it lacks a steering wheel or foot pedal controls.

"We're gravely disappointed that California is already writing a ceiling on the potential for fully self-driving cars to help all of us who live here," Google said in an email response to an AFP inquiry.

California rules-of-the-road for self-driving cars would have the potential to set precedent, and the proposed regulations were seen at sure to slow down the speed with which the technology would go mainstream.

"The primary focus of the deployment regulations is the safety of autonomous vehicles and the safety of the public who will share the road with these vehicles," DMV director Jean Shiomoto said in a release.

"We want to get public input on these draft regulations before we initiate the formal regulatory rule making process."

Workshops were planned to gather feedback from industry, consumer, academic and advocacy groups as well as from the general public.

The proposed regulations call for a licensed driver to be in a self-driving car and able to take control in the event of a technology failure or other emergency.

"Driverless vehicles are initially excluded from deployment," the regulations stated, adding that fully autonomous vehicles would be addressed at some later point in a different set of rules.

- Cyber attack defenses -

Instead of being sold, self-driving cars could be leased for "approved deployment periods," with performance and safety data regularly reported to the department.

The proposed regulations also focused on privacy and cyber-security, saying vehicle makers must let people know what information is collected aside from data needed for safely navigating streets.

Self-driving vehicles would also need to be equipped with self-diagnostic capabilities that detect and respond to cyber-attacks "or other unauthorized intrusions, alert the operator, and allow for an operator override."

Ford this week said that it has a green light to test self-driving cars in California, and should have them on roads in the most populous US state next year.

The car maker officially enrolled in the California Autonomous Vehicle Testing Program and will begin with self-driving Ford Fusion Hybrid sedans, it said in a release.

Ford boasted having more than 100 researchers, engineers, and scientists working in its research center in the Silicon Valley city of Palo Alto.

Google has been testing self-driving cars on California roads for a while, and an array of automobile makers including Audi, Mercedes, Lexus, Tesla and BMW are working on building self-driving capabilities into vehicles.