One of the few sources of objective data is the CA DMV's disconnect and crash reports.[1] There, Google/Waymo has two orders of magnitude fewer disconnects per mile than anybody else testing in California.
A certain level of paranoia in the design is required. The kind of paranoia that aviation engineers have. Volvo gets this - they have dual everything, lots of sensors, and their CEO says that if there's an accident in autonomous mode, it's Volvo's fault. Google got it while Chris Urmson was in charge. The others, not so much. Tesla ... many of their customers believe they have level 4 autonomy. Yes. At least one death is clearly attributable to customer overconfidence in the system.
One thing has become quite clear - expecting the driver to back up the self-driving system on a second by second basis does not work. If the driver can tune out, they will tune out. It's now clear, even to Tesla, that if you don't have level 4 automation, you must keep the driver's hands on the wheel.
A certain level of paranoia in the design is required. The kind of paranoia that aviation engineers have. Volvo gets this - they have dual everything, lots of sensors, and their CEO says that if there's an accident in autonomous mode, it's Volvo's fault. Google got it while Chris Urmson was in charge. The others, not so much. Tesla ... many of their customers believe they have level 4 autonomy. Yes. At least one death is clearly attributable to customer overconfidence in the system.
One thing has become quite clear - expecting the driver to back up the self-driving system on a second by second basis does not work. If the driver can tune out, they will tune out. It's now clear, even to Tesla, that if you don't have level 4 automation, you must keep the driver's hands on the wheel.
[1] https://www.dmv.ca.gov/portal/dmv/detail/vr/autonomous/