Final answer:
A yellow traffic signal or a sign indicating a speed limit or hazard is a warning to slow down. 'No Diving' signs warn against the dangers of diving in shallow water. Recognizing road safety signs is crucial for safe driving.
Step-by-step explanation:
The sign that warns you that you must slow down is typically a yellow traffic signal or a sign indicating a speed limit or a hazard ahead. Specific signs such as 'No Diving' advise against certain actions due to potential dangers, like serious injuries in shallow water. In the context of road safety, a traffic signal at an intersection enforces drivers to slow down and be prepared to stop, significantly reducing the likelihood of speeding through without regard for the speed limit. It's crucial for driver education to include understanding common hazard signs to ensure safety on the roads.