To give volume to the cyclist
The hazard spreader is a plastic rod fitted with a reflector that is usually attached to the left rear of the bike. Its purpose is to encourage other motorists to move away more when overtaking in built-up areas and thus avoid being brushed against by mirrors. The road code stipulates that the lateral distance must be at least 1m in town to overtake a bicycle. Experience has shown that the hazard spreader induces drivers to swerve further to avoid touching the object.