It's not like humans get better at driving with each year of driving. Some become more reckless, people become old, some might think they can have some drinks before sitting behind the wheel and it takes 15 years to get 15 years of experience. What about that over-confident 19 year old who wants to show off their "skills"?
And 15 years of one driver's perception of safe driving is nothing compared to swarm intelligence of AI for driving. If you have 10,000 autonomous vehicles driving for a single day and combine that data at the end of that day to improve driving, that's collectively over 25 years (assuming the human equivalent drives each day of the year) of "knowledge" in one single day. Every day.
Being a father with 2 small kids who drives their kids by bike to kindergarten / school - with a large section of that road is shared by SUVs, vans and bikes (while each side is blocked by parked cars or narrow garage exits built into the building), I can't wait for safe, autonomous vehicles to become the norm.