[vertex-four]

We actually now understand that passing control to a human is seriously dangerous - unless you can do it a minute or so in advance, the human has to switch context from being a passive passenger (or, more likely, actively engrossed in something else) into being an active driver very quickly. Everything up to level 4 automation will cause accidents when the car attempts to hand control to a human.

Of course, there's a very reasonable argument that e.g. level 3 automation might cause fewer accidents overall, even if it kills people when it has no idea what to do, but convincing Joe Public that such a car with such a known flaw is safe is another matter.