I think the mapping between rail and motor vehicle transportation is not necessarily a direct one. Rail (excluding public transit like subway) is more infrastructural and largely unseen, and cars are basically a daily experience for the majority of the population; this fundamentally changes people's perceptions of each.

> Nobody will ride a driverless vehicle provided the explanation that it is, you know, "already an improvement when compared to a typical driver".

I don't necessarily think this is true (perhaps age-correlated?). Let's set aside the issue of whether or not we can do it, for now, and assume that we have a scenario where self-driving cars are safer than human drivers.

In this context, I can easily imagine a political campaign à la "Think of the children!" that paints human drivers as fundamentally unsafe, advocating for a self-driving mandate in urban areas. Perhaps with a Cash-for-Clunkers type of deal to aid the transition. I am not saying this is desirable, merely plausible; it has all the elements of good politics: an easily-grasped bright-line dichotomy, emotional manipulation, and massive corporate benefits (for vehicle manufacturers, self-driving software vendors, and transportation providers like Uber).