In a school zone, what is typically used to signal caution to drivers?

Fluorescent reflective signs are commonly used in school zones to alert drivers to exercise caution. These signs are vibrant and enhance visibility, particularly in low-light conditions or bad weather. The bright colors and reflective materials draw attention, making it clear to drivers that they are entering an area where children may be present, and they need to reduce their speed and remain vigilant.

In contrast, while flashing traffic lights can also signal caution, they may not be as consistently employed in every school zone. Speed bumps serve to slow down traffic but do not necessarily provide visual cues about the presence of a school. Crosswalk signals indicate when pedestrians can safely cross but do not serve the same overarching purpose of warning drivers about the school zone itself. Thus, fluorescent reflective signs are an essential part of traffic safety measures in school environments.