I agree with you that a driver must drive in such a way that he (or she) can avoid collisions. However the law apparently doesn't recognize that, at least in many jurisdictions.
Take for example the curious case recently in Canada where the driver of a car stopped on a highway to rescue some baby ducks who had wandered onto it. A motorcyclist with his child on board slammed into the rear of the stopped car and both dad and child died. The driver of the car has been convicted for negligence and faces "life" (2 x 14 years) in prison.
http://www.dailymail.co.uk/news/article-2663995/Canada-woman-stops-ducks-guilty-2-deaths.html
This is tragic for the family of the dead man and child. It is also tragic for the driver of the car though. Clearly she should not have parked on the highway, but the motorcyclist should not have rammed into a stopped vehicle. That car could just as well have broken down on the road and he still would have slammed into it. Drivers have to pay attention and drive carefully. The first step may be to slow down. Speed limits have become too high.
In 1964 an increase in the New York City speed limit was forced upon the city by the New York State Legislature against protest by the NYC Traffic Commssioner Henry Barnes (of the famous "Barnes Dance" protocol). Today Mayor Bill de Blasio is working to lower it back to 25 in most places, and to 20 in higher risk areas.
We need to back off from the mindset that moving motor vehicle traffic as quickly as possible is properly the primary goal of traffic planners. Safety must be moved into first place.