https://www.techradar.com/news/self-driving-cars-in-california-no-longer-require-a-human-behind-the-wheel

In most US states where self-driving car testing is allowed, laws require that a human must always be behind the wheel, just in case. 

Now, though, California’s Department of Motor Vehicles (DMV) has announced new regulations that will let autonomous autos drive solo – relatively speaking.