What does a yellow traffic sign typically indicate?

A yellow traffic sign is primarily used to provide cautionary information to drivers about upcoming conditions or changes in the roadway. Such signs are designed to alert you to potential hazards or important features that may require attention.

The indication to "look for traffic light ahead" is a common use of a yellow sign, as it prepares drivers to slow down and be prepared for potential stops or changes in traffic flow. This proactive alert reflects the purpose of yellow signs in signaling that caution is necessary.

Other options involve commands or requirements that do not align with the function of yellow signs. The option suggesting to stop immediately implies an emergency or a need for instant compliance, which is characteristic of red signs. When a high speed is advised, it contradicts the necessity of caution implied by yellow signs. Additionally, yielding to pedestrians is typically indicated by the presence of specific signs or markings, often in shapes or colors that carry a different message.

Thus, the correct understanding of a yellow sign emphasizes its role as a cautionary alert, particularly in directing drivers to prepare for forthcoming traffic signals.