When is it permissible to use your horn while driving?

Using your horn is permissible primarily in situations where it can serve as a warning to other drivers, especially in potentially dangerous circumstances. For instance, if you are approaching an intersection where another driver may not see you, or if a vehicle in your vicinity is about to make a sudden maneuver that could lead to an accident, sounding your horn can alert the other drivers to your presence and help avoid a collision. This use of the horn focuses on safety and is a responsible driving practice aimed at preventing accidents.

In contrast, the other options involve uses of the horn that are not appropriate or may not contribute to safety. Expressing frustration with another driver is not only ineffective but can escalate tensions on the road and lead to aggressive driving. Greeting friends while driving can distract you and other drivers, detracting from the primary focus of safe driving. Communicating with pedestrians may not be effective, as pedestrians should rely on visual cues and clear signals rather than auditory ones from vehicles, which can be misinterpreted or ignored. Overall, the central purpose of using a horn is to enhance safety on the road, particularly in warning other drivers of immediate dangers.