There are far too many road signs! We are inundated with them, sometimes having 3 or 4 signs indicating the same hazard, sometimes within 2 metres of each other. There is a real danger of information overload for drivers and important signs being missed because of unimportant ones.
It is an important ability in learnng to drive that we learn to read the road and that includes spotting hazards ourselves rather than relying on the authorities to tell us about them. For example, do I really need to know that the road on the left contains humps for 3/4 mile? If I am clever enough to use it as a short cut, then surely I can see the humps for myself? A silly example I know but there are many, many more.