How many times must the horn be sounded when backing up a vehicle?

The correct practice for sounding the horn while backing up a vehicle is to sound it twice. This is a safety protocol designed to alert anyone nearby that the vehicle is about to move in reverse. By sounding the horn twice, the driver communicates their intention to back up, giving pedestrians and other vehicles adequate warning to clear the area. This practice is particularly important in situations where visibility is limited or there may be potential blind spots. Therefore, sounding the horn twice serves as a clear and effective warning mechanism to enhance safety during backing maneuvers.