Earlier quoted context omitted.
One of the lessons of these first steps toward autonomous driving is: if you have a big array of sensors, and plenty of on board computing, then many driving problems, especially in semi controlled circumstances, like open highways, are within our grasp now. The sensors and computing are expensive now - especially lidar. But that's an engineering problem, as you suggest.
The problems in automated driving are not in controlled and normal circumstances but in all the edge cases and exceptions.
I was trying to address the question raised by the comment above: is this a problem of principles or of engineering, by saying that for a big (proportion TBD) segment of routes, it's engineering. Put onboard a bunch of sensors and computer power.