Under nominal and expected driving conditions...
And that's where everything goes wrong. You know, under "normal and expected conditions" there isn't any dogshit on the sidewalk, but guess what?
I'm aware that not every situation is deal... but a driver who's actually otherwise competent should be able to recognize those situations the instant that they arise..
Unless of course they're busy with whatever else they do under "normal and expected conditions." Switching attention takes time---there's a reason why sprinters are not chatting on the phone right up until they hear the starting gun.