"Andy Hall" wrote in message
...

The only non-arguable definition of "too fast" is whether or not the
vehicle was exceeding the speed limit. That can be precisely measured.
Everything else is subjective.

You can precisely measure the distance that the driver could see and the
stopping distance of the car.
If the stopping distance exceeds the visibility distance he was driving too
fast whatever the speed limit.
It is important to remember that we operate variable speed limits.. its the
safe speed or the speed limit whichever is lower.