There was a time when autonomous test cars required a safety driver behind the wheel to intervene if anything goes wrong. However, a permit from the California Department of Motor Vehicles has allowed companies such as GM's Cruise to test self-driving cars on public roads without a backup driver behind the driver.

Now, Chinese driving startup WeRide is the latest company to be added to that list. Backed by the Renault-Nissan-Mitsubishi alliance, WeRide is the seventh company to receive a driverless testing permit after AutoX, Baidu, Cruise, Nuro, Waymo, and Zoox.

The permit enables WeRide to test two autonomous passenger cars without a human safety driver behind the wheel on specific streets in the San Jose area of California.

During the tests, the driverless cars will not be allowed to exceed 45 mph. Tests will be carried out on Monday to Friday in the daytime but will not be allowed in heavy fog or rain. WeRide is also testing its driverless car in the company's home city of Guangzhou in China. It isn't known which cars will be used to test the autonomous technology, but WeRide's taxi fleet includes the Nissan Leaf, the electric Nissan Sylphy Zero Emission, and the Lincoln MKZ.

It also isn't known if a safety driver will be in the passenger seat, but California Department of Motor Vehicles requires companies with driverless testing permits to report any collisions involving a test vehicle within ten days. Companies applying for a driverless permit also need to provide evidence of insurance or a bond equal to $5 million and prove its cars have Level 4 or 5 autonomy and can be operated without a driver.

WeRide predominately operates in China, but the permit suggests the Chinese driverless car startup could expand its robotaxi service to the US in the future.