In which situation is it advised to signal before passing a vehicle?

Signaling before changing lanes is crucial for maintaining safety and communication on the road. It alerts other drivers of your intentions, allowing them to anticipate your movements and react accordingly. This is an essential part of safe driving practices because it reduces the risk of accidents, particularly when you are preparing to enter another lane where other vehicles may be present.

The other scenarios listed do not specifically require signaling in the same way. For instance, while approaching a traffic light, your next action may depend on the light's color rather than a lane change. Signaling is not only limited to highways as it applies in all driving situations, including city streets and residential areas. Additionally, when driving in reverse, other visual checks and situational awareness are more critical than signaling, as vehicles may not expect you to be reversing and might not be aware of your presence.