Final answer:
A traffic light that turns yellow after being green is a signal cautioning drivers to prepare to stop. It helps in regulating traffic flow and ensuring pedestrian safety at intersections.
Step-by-step explanation:
A traffic light that is green when you first see it, but will soon turn yellow is known as a signal that is about to change to its cautionary state, indicating that drivers need to prepare to stop. The presence of traffic signals plays a critical role in both vehicle and pedestrian safety.
Traffic signals help to regulate the flow of traffic, prevent speeding, and provide safe crossing points for pedestrians. Specifically, in areas where vehicle speeds and pedestrian traffic are of concern, a well-timed traffic signal can significantly reduce the risk of accidents and ensure that pedestrians can cross at appropriate and safe times.