It's not that I say 50ft is the only zone, but its my main focus, that and traffic around me (Mind you, this is all highway) With the Comma, it moves out a good bit, Allowing me to process more of the future traffic going on and the more edge cases that might come up at highway speeds. Also its vision and radar based so it keeps me 250ft+ from the car in front of me and keeps speed, it won't ever change lanes. This is why its more of a LKAS with better settings.
Of course there are cases the system doesn't work at all and is not well suited for surface roads very well.
Its behavior is very predictable and easy to feel when its seeing something I'm not. (Slowing down to match speed 1:1 with the car in front of me when they let off the gas is a common example)
50 ft is 15 meters and change, at regular car speeds that is much shorter than your reaction speed. It's essentially an accident waiting to happen. At highway speeds you should be looking about 200 ft ahead of you for safe driving. See the 'two second rule', and that's for clear skies, daylight:
Every day I drive, I see dozens of incidents where I think someone should be ticketed for reckless driving: tailgating, excessive speed, unexpected lane changes, etc
They never, ever are. We do not enforce good driving except after people die (or even then, vehicular homicide has low sentences).
