Just curious, how does one prove 100% safe? Even if Tesla's were show to be safe on every road in existence there are always too many variables. Weather, construction, road condition, other drivers, objects falling into the roadway, on and on.
There is some level of reasonable safety that should be expected, but proving 100% safe isn't a realistic goal, nor is it even a standard for existing automobiles.
I'm not sure you could get to 100% safety. See any rail system in the world, however I'm more comfortable with our general rate of derailments I think (I haven't looked into the statistics). So I think we could get to a 'safe' system that looks like 'automated freight carrying in a special lane that is restricted, has built in 'hinting' and only if all the freight carrying vehicles are networked' Let the truck drivers get in that lane, fully engage automatic pilot and hopefully one day take a nap, to be awoken upon approach to their destination where they will take over, move out of the special lane, exit the freeway and proceed to their dropoff/pickup.
There is some level of reasonable safety that should be expected, but proving 100% safe isn't a realistic goal, nor is it even a standard for existing automobiles.