Safety Engineer wrote:
In this case we could end up with two primary causes in tandem:
...
The two primary factors are the cause of Driver A's action combined with the inability of Driver B to drive in a manner that allowed enough of a gap to allow them to deal with a hazard.
The article provided:
twice infers that Driver A (henceforth 'Ford SUV') was traveling at 65MpH prior to its brakestand,
quantifies 'Ford SUV's brakestand as -30MpH,
quantifies 'Ford SUV's speed after the brakestand as 35MpH
NEVER suggests or infers that 'Ford SUV' was traveling in excess of the posted speed 'limit'
What does the excessive portion of 'Ford SUV's brakestand qualify as? A primary cause? Or a secondary cause?
The reason why I ask, is because ...
I classify 'Ford SUV's brakestand as the second erroneous event and the second primary cause.
I classify the excessive magnitude of the brakestand as the third erroneous event, but merely a secondary cause.
'Ford SUV's errors are of a fundamentally different nature than the errors of Driver B (henceforth 'Pontiac G6'). Though the collision would not have occurred without 'Pontiac G6' (or any other vehicle, FWIW), 'Ford SUV' made active mistakes directly precipitated by the speed camera van 1st, followed by his heuristic misgivings.
Meanwhile, 'Pontiac G6' made passive mistakes all precipitated by 'Ford SUV'. In my mind, 'stopping short' or 'brakestanding', when it is not required to prevent a collision AND is also factor in a collision, significantly mitigates the responsibility of the following car. As the article states, 'Pontiac G6' did not expect anything untoward to happen (she certainly didn't know about the speed camera van.)
Oh, and if the speed camera van intended to prevent driving above the posted speed 'limit', it would have been positioned so as to avoid surprising 'Ford SUV'.
However, since it was instead positioned to surprise 'Ford SUV', and in fact did surprise 'Ford SUV', I classify it as the initial, the primary, and the linchpin causal factor of the collision.