Comment by akoboldfrying

AFAICT at least 2 people in this thread don't seem to think that visibility -- a function of, among other things, weather and time of day -- influences driving safety. I find this amazing.

The point of terryf's example was to point out that for practical reasons, existing laws don't capture every relevant variable. I (but not everyone, it seems) think that visibility obviously influences safety. The point I want to make is that in practice the "precision gap" can't be perfectly rectified by making legality a function of more factors than just speed. There will always be some additional factor that influences the probability of a crash by some small amount -- and some of the largest factors, like individual driving ability, would be objected to on other grounds.