The problem isn't the 99.99%, but the .01% where the right thing has to be done quickly. Take for example the small tunnel near me. It's a 4 lane, 2 in each direction. While being repaired it's down to a two lane, with cones all over telling you to move into the other direction lane to proceed. Cops all over directing traffic, really it's a pretty chaotic situation with no defined way to navigate it other than taking in what is going on and doing the right thing. No two cops direct traffic the same way, no two construction zones are set up the same way. Each one is a learn as you go, something humans excel at even if it's a 16 year old kid who just got their license. This is the Achilles heel of automated driving and we're quite a number of years away from sorting it all out.