i know nothing said:But how could you enforce such a thing?
The way it always was enforced... Policemen.
I don't want anything that wasn't done before speed cameras came into use, as I said earlier, policemen used to use the speeding laws as one way of punishing bad drivers, not as a means to make money.
It's easy to look at people and tell whether they are driving appropriately, and there's a lot more to it than simply what speed they are doing. Speed is a very poor judge of driving quality.