I do not agree that laws reduce peoples speed or the number of people speeding. And I believe that the facts prove this out. So I would start by saying, I don't believe you have isolated a real problem.
However, for the sake of argument, I will assume that you have somehow proven speeding increases the danger of potential accidents by a marginal amount, or rather that the laws decrease it.
Reducing the number of accidents by whatever amount doesn't justify the extortion and fishing carried on by police that use it as an excuse. To review it's actual implications, the total money extorted by the police in both tickets, legal fees, taxes, and excessive force far exceeds the value saved by preventing the accidents that you would claim are prevented by the laws, as a whole, making it a net loss in society.
If you want more detail. Provide some facts, evidence to support how much speeding laws reduce speeding and accidents so that I can compare/contrast.
The Philosophy Of Liberty -