The 4 colors of the DGT fog to warn of the level of visibility on the road

Driving in fog is one of the most stressful situations we can encounter on the road.

Oliver Thansan
Oliver Thansan
02 January 2024 Tuesday 16:31
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The 4 colors of the DGT fog to warn of the level of visibility on the road

Driving in fog is one of the most stressful situations we can encounter on the road. At certain times of the year, as is now the case in winter, the combination of low temperatures and the humidity typical of this season contributes to the formation of fog banks that limit visibility and increase the risk of accidents.

With these adverse weather conditions, traffic authorities recommend drivers take extreme caution behind the wheel. In addition to reducing speed and using the fog lights, it is essential to maintain an even greater safety distance than usual, since the surface may be wet and the possibility of aquaplaning increases as the grip of the tires on the asphalt is reduced.

Regarding overtaking, it is prohibited to overtake other vehicles on two-way roads in dense fog and it is not recommended to do so if visibility is not completely clear. If the driver chooses to leave the road and look for a safe place until it clears, in no case should he stop on the shoulder.

To warn and inform drivers of the density of fog and traffic restrictions, the General Directorate of Traffic (DGT) uses color codes. Each color (green, yellow, red and black) is associated with the visibility distance and the road conditions at that time so that motorists can adapt their driving mode. Black means the road is closed to traffic.

The majority of traffic accidents that occur in foggy areas tend to be collisions with the vehicle in front due to not respecting, among other things, the safety distance. For this reason, the DGT establishes the black level when the visibility distance is less than 40 meters and driving cannot be done in safe circumstances.

On some highways where fog banks are common, Tráfico has installed a system of intelligent beacons to redirect traffic to other roads when weather conditions do not allow road safety to be guaranteed. Furthermore, on the stretches of highway where fog usually settles, more powerful and brighter beacons have been placed. Its mission is to warn the driver that another vehicle is traveling in front of him.

The beacon is activated when it detects that we are approaching the car in front of us, illuminating a red light at the top. As the first vehicle advances, the remaining beacons light up in its path, providing the driver following it with the ability to see it at a distance of approximately 100 meters, allowing them to circulate safely.

Traffic reminds that in the event of a fog bank it is mandatory to turn on the dipped headlights and front fog lights. The rear fog lights only need to be turned on if the fog is very intense. Additionally, it is suggested to use road markings as a reference or follow other vehicles without forcing the road. Likewise, it is advisable to avoid the use of high beams, as these can bounce off the fog bank, generating a dazzling effect instead of improving visibility.