But my point, and the one made by the article as I understand it, is that you wouldn't even have to do any of that initially. The vast majority of the driver's time is spent just cruising on the highway. That's the part you want to work on automating first, both because it provides the greatest cost savings, and because it's the easiest to solve technically.

Lexus automated the most hated driving maneuver for all car drivers - parallel parking, and Google's had decent success w/their self driving Prii fleet... it's hard, safety would be the #1 concern, but w/enough human brainpower and some decent hard realtime OS-es, it should be more than doable.