Explain to me the difference between these three signs: 1. a bicycle on a blue circle, 2. a bicycle on a white circle outlined in red, and 3. a bicycle on a blue square.
On the other hand having to read all that in text while you're riding by isn't very reasonable either. Complex signage is only as good as your knowledge of it, which maybe is why passing a driving test in Europe is so much harder; it requires knowledge we just get from being able to read in the US.