What does it mean when a traffic signal turns yellow?

When a traffic signal turns yellow, it indicates that the signal is about to change to red, which is a warning for drivers to prepare to stop. The purpose of the yellow light is to provide a transition period where drivers are alerted to the impending change in the traffic signal. This is intended to enhance safety by preventing sudden stops in heavy traffic and allowing drivers to make a decision about whether they can safely stop or should proceed through the intersection before the light turns red.

In this context, while it’s true that some might consider proceeding with caution, the primary function of the yellow light is to alert drivers to the necessity of stopping when safe to do so. This is crucial in maintaining the flow of traffic and reducing the risk of accidents at intersections. Other choices refer to different scenarios: a signal turning green does not relate to the yellow light, as does the implication of a pedestrian crossing, which is indicated by other signage rather than a change in the vehicle signal.