• I refuse to drive in very dense fog.
  

In this toolbox we devote attention to driving in fog. In this toolbox we give you tips that can help avoid chain collisions and skidding accidents. This way we arrive safely at work and return home without a scratch, albeit later than usual.

To better understand the following tips, it is good to know what fog really is, how it emerges and not to underestimate the risks of driving in fog.

What is fog and how does it emerge?

• Fog is a weather phenomenon, whereby small droplets float in the air, which reduces visibility.
• Fog can form due to the cooling of very humid air or by mixing cold with warm humid air.
• The formation of fog depends on many factors, such as air pollution, vegetation, topography and the proximity of open water.
• Smog acerbates the dangers of fog; because fog is very low-hanging, it prevents the harmful gases emitted by cars from rising and they stay hanging above the road, which further worsens visibility.
• Fog often starts with a few patches and you might think: ‘Just another fog patch, no need to brake’. This while another road user ahead of you has a different reaction, because he/she has entered a dense fog bank and due to a lack of visibility is braking hard.
• In other words, the driver ahead of you starts braking, while you have not yet realized the seriousness of the fog bank and continue to drive at full speed.
• An additional danger at low temperatures is that fog can freeze up, creating the greatest risk of driving in fog.
• Most major traffic accidents (you could say road disasters) occur under these weather conditions.
  

• Chain collision
• Poor visibility
• Slippery conditions due to freezing fog droplets
• Time pressure during fog can have catastrophic consequences
  

• Be prepared for fog
• Halve your speed and double your distance
• Never solely depend on the rear lights of the car in front of you
• Know where your fog lights switch is located
• Never pass in fog
• Use your low beam and not your high beam
• Only use your rear fog lights when visibility is less than 50 metres
• During daytime fog, the automatic headlight switch does not turn on
• When driving long trips in fog take more breaks
• Be extra alert to freezing fog
  

When to turn on fog lights and when not?

When to turn on fog lights and when not? Legally, it is mandatory for every car to have fog lights. Despite the fact that fog lights are mandatory, there also are specific rules as to when you are allowed to turn them on. By far not everyone abides by these rules and a car’s fog lights often are also turned on in case of bad weather. So, when are you allowed to turn them on and when is this not allowed?

When to use fog lights

Having fog lights at the rear of the car is mandatory. They are optional at the front, but most cars are nevertheless still equipped with them. But when should the fog lights be used? When should you turn on the fog lights in front and when should you turn them on at the rear of the car? Dutch legislation is very clear on this topic.

When to turn on the rear fog lights

The rear fog lights may only be turned on when visibility is less than 50 metres. In practice this means that at a normal distance behind the preceding car, the rear of this car is no longer visible. If you can still see the car in front, then you do not yet have to turn on the rear fog lights. The cars behind you can still see you sufficiently clearly.

When to turn on the front fog lights

You are allowed to use the front fog lights when visibility is less than 200 metres. Outside the built-up area you can use the hectometre markers as a point of reference. These markers are spaced 100 metres apart. Inside the built-up area you can use the distance between the lampposts as a point of reference. These lampposts are generally spaced 50 metres apart.

When not to turn on the fog lights

When to turn on the fog lights is difficult to assess for many road users. The front fog lights may be turned on when visibility is less than 200 metres, but they are often turned on for show, because that fits a car’s style. In addition, many people turn on the car’s fog lights when there is severe rain or a snow storm. In all of these situations, the use of fog lights is not permitted and you could be fined.

How to turn on the fog lights

Now that you know when to turn on the fog lights, there is still one more question: how do you turn them on? Because fog lights seldom need to be turned on, the buttons may not be easy to find for everyone.

The front fog lights are designated by a symbol of a lamp that shines downward with a vertical squiggle line through it. This symbol is lit up in green.

The rear fog light is designated by a symbol of a lamp that shines horizontally also with a vertical squiggle line through it. This symbol is lit up in orange or red, however. Another difference is that the symbol for the front fog lights points to the left and the other symbol points to the right.