Which lights should you use when you are driving in fog?

Using low (dim) headlights in fog is correct because they help reduce the amount of light that is reflected back at you by the fog, rain, or snow. High beams can make visibility worse in foggy conditions, as they illuminate the water droplets in the air, creating a glare that can hinder your ability to see. Parking lights are not designed for use while driving and do not provide adequate illumination, while turn signals are used to communicate your intentions to other drivers rather than to improve visibility. Low beams are specifically designed to give you the best visibility without reflecting back into your line of sight in adverse weather conditions.