Of course, the computer has always had a human driver to take over in tight spots.
Musk said it would be twice as safe as a human driver.
The final stage would then be "driver off", or without a human driver inside.
That's the number of miles, on average, that it takes a human driver to kill someone in the United States.
Uber recently began testing a self-driving car in Pittsburgh carrying passengers, with a human driver for backup.
Each vehicle was outfitted with multiple shutdown devices and trailed by a human driver with a kill switch.
In addition, it could make trucking more efficient, allowing, for example, a human driver to rest in the sleeper cabin while the truck takes the wheel.
Picking up and dropping off customers may be trickier without a human driver to wave to, for example, or to point out a safe place to stop.
GPS devices, for example, could provide all sorts of decision support, allowing a human driver to explore options, view maps and alter a route.
Consumer Watchdog, a California-based campaign group, said the report shows that self-driving cars still need a human driver behind the wheel.
During that time Google has said its autonomous vehicle was only involved in one accident, which occurred when a human driver took control.
