For general acceptance I think it has to be better than how good the average human thinks they are at driving.
Secondly, its dumbest errors have to be better than what the average human thinks their dumbest errors would be. If there is an accident and every one thinks they would never have made this error, it will crush the acceptance.
Looking at the general accidents stats and saying to people that, on average there are less deaths on the road but they might die in a stupid accident they would never have been into, had they been driving themselves, will be a very hard pill to swallow. Most people prefer to have the illusion of control even if statistically it means worse expectations.
Secondly, its dumbest errors have to be better than what the average human thinks their dumbest errors would be. If there is an accident and every one thinks they would never have made this error, it will crush the acceptance.
Looking at the general accidents stats and saying to people that, on average there are less deaths on the road but they might die in a stupid accident they would never have been into, had they been driving themselves, will be a very hard pill to swallow. Most people prefer to have the illusion of control even if statistically it means worse expectations.