Driverless cars without a human operator will begin rolling out on California city streets in April, following legal approval by the Department of Motor Vehicles to institute ground rules and issue permits to auto manufacturers and tech companies that want to test their autonomous cars.

Currently, autonomous vehicle testing on California roads — such as that by Waymo and General Motors — requires an engineer or other person sitting behind the wheel, reports the Sacramento Bee. The new regulations, on the other hand, will allow companies to test unmanned vehicles being monitored from remote locations.

Some 50 companies have registered with the state to do some kind of testing, though it is unclear when they will seek permits and what locales they will select for their testing.

Under the new DMV rules, in order to obtain a permit, companies have to show state and federal officials that the vehicles meet safety standards and comply with traffic laws, reports The Bee.

In addition, testing companies must notify any California city in which it plans to test its cars. The manufacturer must also supply the state with a communication link between the vehicle and a "remote operator" who would monitor a vehicle being controlled by an on-board computer.

The rules also mandate that test companies identify the owner of the test vehicle in some manner to the public on the street — in the event the vehicle were to be involved in a crash. In addition, all autonomous cars must carry proof of insurance. Companies must provide police with a means of deactivating the car as well as communicating with the manufacturer, reports the San Francisco Examiner.

Finally, according to the report, vehicles without steering wheels or pedals would be legal for street tests, but only if the manufacturer gets an exemption from the National Highway Traffic Safety Administration.

In March, California will also allow automakers and tech companies to obtain a second permit that will allow autonomous cars to be used commercially on city streets, but only after meeting specific safety test parameters.