According to General Directorate of Traffic (DGT), front fog lights and rear fog lights will help you see better and be seen. In conditions of poor visibility, the speed must be reduced, adapting it to the circumstances, so that it is possible to stop within your field of vision. Also increase the frontal separation to avoid reaching: at 50 km/h and on wet ground, a car does not stop before 30 meters. If the fog is very thick, it is better to abandon the road and wait for it to clear.
With the changes in the weather that we are seeing these days, it is common for fog banks to be present in cities and roads, so it is necessary to know in which conditions we can use the fog lights and in which we cannot, since their use Inadequate use can result in a fine of up to 200 euros.
They can be on the high/low beam controls, but also on a separate button located on both the center console and the sides. That is why it is advisable to read the car’s instruction manual and memorize how to put them on and take them off, so as not to have doubts or take your eyes off the road if we are surprised while driving by a fog bank and we do not know its location.
The truth is that fog lights should only be used to see and be seen in low visibility conditions.
Thus, the front fog lights are used in conditions that significantly reduce visibility, isolated or together with short and long range lights. It is not mandatory and not all vehicles are equipped with it. They can also be used at night on narrow roads (less than 6.5 m wide) with successive marked curves. Poorly used, it dazzles from the front and is reflected in the rearview mirrors.
As for the rear fog light, it has a deep red color, to make the vehicle more visible from behind. We can equip one, on the left or in the center; or two, on the outer edges. It is mandatory for cars (except motorcycles), only in unfavorable conditions: with thick fog, very heavy rain or heavy snowfall. It must be turned off during traffic jams or if the fog disappears, so as not to dazzle the drivers behind you.
According to the Traffic Regulations, fog lights can only be used in case of fog, very heavy rain, storm, heavy snowfall or dust cloud. Regarding the front light system, it says that, when there are conditions of low visibility due to fog, heavy rain or a cloud of dust, even during the day, you must have the lights on, whether fog, dipped or long-range. and clarifies that the fog light can only be used in those cases. They may also be used on narrow roads with many curves, meaning those that, having a road width of 6.50 meters or less, are marked with signs indicating a succession of curves close to each other.
Regarding the rear fog light, it says that it can only be used when weather or environmental conditions are “especially unfavorable.” This means thick fog, very heavy rain, heavy snow, or dense clouds of dust or smoke.
To avoid a fine, but above all to avoid causing inconvenience to the drivers with whom we share the road, we have to avoid using the fog lights in light rain conditions, since the strong brightness they produce is amplified by the drops that are generated. They deposit on the windshields of other drivers, causing discomfort to their visibility.