What does a yellow traffic light mean?

A yellow traffic light indicates that drivers should prepare to stop because the light is about to turn red. This warning sign gives drivers a chance to reduce their speed and safely come to a stop before the traffic signal changes. The purpose of the yellow light is to enhance safety and ensure that drivers are alerted to the imminent change in traffic conditions, allowing them to make informed decisions about whether to stop or proceed with caution.

In contrast, the other options suggest actions that are not aligned with the intended function of a yellow light. Proceeding with caution fails to emphasize the need to stop, which is critical as the light transitions to red. The suggestion to speed up to clear the intersection contradicts the safety principle, as it may lead to accidents if the light changes before the driver can safely exit the intersection. Stopping immediately may not always be safe, especially if one is too close to the intersection, thus highlighting the need to prepare to stop rather than applying the brakes suddenly without consideration of the stopping distance.