It appears obvious that the human condition will put too much trust in the car. So, let's not let all humans operate self-driving vehicles for now. Let's say we instead begin with a very limited license that can only be obtained by specially-trained drivers familiar with expectations for device operation and manual override. Find a fleet of taxi drivers in a municipality, for example, or perhaps some transport vehicles that just bus passengers between an airport and hotels. Beta test car operations to determine how much driver-intervention is required at this stage in SDV technology development, then make recommendations from what is learned on how to proceed to the next step?
Either that, or start building dedicated highways that only allow self-driving vehicles. And only allow SDV-mode while on those highways.