Not sure that's fair - the number of accidents in human-driven vehicles varies significantly by the human driving it. Do you compare with the teen that just obtained their license and is more interested in their phone than in driving properly, or the 65-year old doctor who's been driving for work and other purposes every day for the past 40 years? According to https://injuryfacts.nsc.org/motor-vehicle/overview/age-of-dr... it's at least a 6x difference.
You compare what matters — mean accidents per mile driven. And like any actuary, you can compare distributions with finer granularity data (location, tickets, ages, occupations, collusion severity, etc). None of this is new or intractable. We can have objective standards with confident judgements of what’s safe for our roads.
As an aside, public acceptance of driverless cars is another story. A story filled with warped perspectives due to media outlets stoking the audience emotions which keep outlets in business — outrage, fear, and drama. For every story covering an extreme accident involving human drivers, there might be 100 stories covering a moderate driverless accident. No matter how superhuman autonomous cars perform, they’ll have a massive uphill battle for a positive image.
I think you compare it to the average as that's who you are encountering when on the road. You have no way of selecting the other drivers to bias toward the doctor.
Teens who’ve just gotten their license are often quite good drivers. It’s after that when they drive poorly. (This also applies to adults, to a lesser extent.)
