The process of it becoming good enough will be more gradual, with corporate interests lobbying for whatever is most marketable at the time. There will be no singular convention on driving where the philosophical question at the root of policy gets resolved - research will show new drivers benefit most, so at first first-time drivers might be obliged to have some AI backup then there will be some incremental movement as the political climate is favorable.

Not to go off on a tangent, but I think gun control is a useful example of what I'm talking about: it's so easy to make people fight bitterly over minutia while ignoring the core philosophical questions entirely (government monopoly on violence, civilian relationship to government, civilian disarmament), an earnest discussion of which would likely be more disruptive to either overarching agenda than losing any court case (by calling other policy into question - like militarized police who do not even see themselves as civilians anymore).

So nVidia releases a better self driving AI than Tesla, and everyone is comfortable with letting it drive on the highway for you. Each step will be fairly uncontroversial until at some point we're all comfortable with the thing and someone only wants to make it mandatory for some small segment of drivers, which itself will not draw much controversy because classic non-AI cars with manual transmissions and such will only be in the realm of enthusiasts and collectors.