What must a vehicle be equipped with if it has fog lights at the back?

A vehicle that is equipped with fog lights at the back must have two red fog lights. This requirement is based on safety regulations designed to enhance visibility for other drivers during foggy or adverse weather conditions. The use of two red fog lights creates a more pronounced signal to drivers behind the vehicle, alerting them to the vehicle's presence and position on the road when visibility is poor.

Having two red fog lights also ensures even more effective communication with other road users. In situations where visibility is significantly reduced, a symmetrical light pattern helps prevent confusion and improves overall road safety. The presence of only one fog light might not provide enough visibility, while the options of white or yellow fog lights are not compliant with the standard regulations, as fog lights must be red to designate their specific purpose and to distinguish them from other lighting types.