[glenra]

> I think I've seen at least a prototype Waymo car (it was exhibited in the Computer History Museum) that was designed without the steering wheel and pedals for a human to use. That wouldn't work so well given that the car might pull over and be unable/unwilling to drive anymore.

It'd be fine - you just need to have some backup option. A small joystick or two behind some panel, or screen control, or perhaps you control the car with a phone app. It's like having an emergency spare tire - you just need a minimal driving UI that can be used in case of emergencies but users otherwise don't need to see or deal with. It can be inconvenient and speed-limited, since you don't expect to use it much.

Though if there's decent connectivity an obvious intermediate option is remote operation. Some human who is really good at driving might take over for a bit, driving your car from the comfort of their own home or office if you're not comfortable doing so yourself using the backup control pad.