Fog significantly reduces visibility, sometimes to less than 100 metres, making it difficult for drivers to see other vehicles, pedestrians, or road signs. Dense fog can also distort perception, making distances appear shorter or longer than they actually are. In addition, wet road surfaces caused by fog can lead to slippery conditions, increasing the risk of skidding and collisions. These factors make driving in fog a potentially dangerous activity, especially for those unfamiliar with such conditions.