What is the primary function of a yellow traffic light?

The primary function of a yellow traffic light is to signal that the light is about to change to red. This warning serves to alert drivers that they need to prepare to stop if it is safe to do so. A yellow light typically follows a green light and is an important part of traffic signal systems, as it provides a transition period, allowing drivers to react appropriately. It encourages caution and helps prevent accidents by giving drivers a brief moment to decide whether they can safely stop or if they need to proceed through the intersection before the light turns red. Understanding this function is essential for safe driving and compliance with traffic laws.