Reduce your speed in bad weather

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Rain, fog and snow: the speeds imposed in bad weather in Belgium and the general duty to adapt your pace to conditions.

Coverage, Reduce your speed in bad weather

Lesson objectives

Understand why and how to reduce your speed according to weather conditions (rain, ice, fog) Master braking and stopping distances on wet, snowy or icy ground Know lighting obligations and weather alert signals

The fundamental rule: adapt your speed to circumstances

Article 10.1 of the code imposes three permanent obligations: adjust your speed according to the presence of other road users, weather conditions , road condition and visibility; maintain a sufficient safety distance from the vehicle ahead; and above all be able to stop in any circumstance before a foreseeable obstacle . In other words, the displayed limit, 30 km/h in built-up areas in Brussels, 50 km/h in Flanders and Wallonia, 70 or 90 km/h on ordinary roads depending on the Region, is a ceiling , never a speed to maintain. As soon as rain, ice or fog sets in, driving at the displayed limit is already a violation of article 10.1.

Heavy rain on urban road

Rain: drastic increase in braking distance

On wet pavement, water forms a film between the tire and the road and grip drops: the braking distance can be doubled compared to dry ground. This is the distance needed to stop the vehicle once the brake is applied, not to be confused with the safety distance you leave in front of you, expressed in seconds, which must be increased from approximately 2 to 3 seconds on wet ground.

In case of heavy rain: slow down significantly before entering a curve, never during the curve. Braking in the middle of a curve on slippery pavement causes a loss of grip and a risk of skidding.

Aquaplaning

Phenomenon where tires slide on a layer of water and lose contact with the road surface. Aquaplaning can occur even at speeds below 100 km/h if water accumulates on the pavement.

A15

A15 - Slippery road. The road may be particularly slippery in case of rain, ice, gravel or fallen leaves. Avoid sudden braking and sharp steering. Increase safety distances and adapt your speed to conditions.

Ice and snow: minimal grip

On snowy or icy ground, grip is extremely reduced: the braking distance can be multiplied by four or more. The safety distance must be increased accordingly, allow at least 4 seconds between your vehicle and the one ahead of you, instead of 2 seconds on dry ground. At 120 km/h , this represents approximately 133 m .

Important: never modify tire pressure according to weather conditions. Always respect the pressure recommended by the manufacturer, which is calculated to provide the best performance in all conditions.

There is no "ice" signal or "fog" signal

The code contains no danger signal specific to ice, snow or fog . The risk of slippery pavement due to ice or snow is announced by the A15 signal supplemented by an additional panel provided for this purpose. Beware of exam questions that invent an "A16" or an "A18": these numbers do not exist in the series of danger signals, which is numbered A1, A3, A5, A7… A13, A14, A15, A17, A19, A21…

Snowy road with reduced visibility

Fog: reduced visibility and mandatory lights

In case of fog, reduced visibility prevents you from seeing obstacles in time: slow down gradually when entering a fog bank, without sudden braking. Two thresholds not to be confused: dipped headlights are mandatory as soon as it is no longer possible to see clearly up to approximately 200 metres (art. 30); the rear fog light becomes mandatory when fog or snowfall reduces visibility to less than approximately 100 metres .

Fog is not signalled, it is endured

No road sign announces fog. Your only obligations are therefore those of article 10.1 , adjust your speed to your field of visibility and be able to stop before a foreseeable obstacle, and those of article 30 on lighting: dipped headlights as soon as visibility drops below approximately 200 m , rear fog light below approximately 100 m .

The two visibility thresholds: 200 m and 100 m

Approximately 200 metres : threshold that makes the use of dipped headlights mandatory, day and night, as soon as it is no longer possible to see clearly up to that distance (art. 30). Approximately 100 metres : threshold that makes the rear fog light mandatory in case of fog or snowfall. In case of heavy rain , the rear fog light is mandatory without any visibility condition .

Summary table: safety distance according to conditions

Speed Dry road, 2 s Wet road, 3 s Snow or ice, 4 s 50 km/h 28 m 42 m 56 m 70 km/h 39 m 58 m 78 m 90 km/h 50 m 75 m 100 m 120 km/h 67 m 100 m 133 m

Lighting obligations in bad weather

Dipped headlights: mandatory between dusk and dawn, and in any circumstance where it is no longer possible to see clearly up to approximately 200 metres , so also during the day, in rain, fog or snow (art. 30). Front fog lights: they can only be used in case of fog, snowfall or heavy rain . They may replace dipped headlights or main beam headlights, or be switched on simultaneously with them. Rear fog light: mandatory in case of fog or snowfall reducing visibility to less than approximately 100 metres , as well as in case of heavy rain . The code specifies that this light cannot be used in other circumstances .

Frequent exam trap: the rear fog light is mandatory in heavy rain without any visibility condition , whereas fog and snowfall require visibility reduced to less than approximately 100 m (art. 30). Second trap: this 100 m threshold concerns only the rear fog light, dipped headlights, on the other hand, are required from 200 m visibility. Third trap: outside these three situations, switching on the rear fog light is prohibited .

Practical driving strategies in bad weather

Slow down gradually well before entering an area of fog or heavy rain Increase the safety distance : article 10.1, 2° only requires a "sufficient" distance, without a specific figure. The rule of thumb of 2 seconds on dry road, 3 seconds on wet road and 4 seconds on snow or ice is a teaching rule, not a legal text Avoid sudden braking , which causes skidding on slippery surfaces Slow down before the bend , never during Switch on your lights as soon as visibility drops below approximately 200 m, even in broad daylight Do not use the rear fog light except in fog, snowfall or heavy rain: elsewhere, it is prohibited and it dazzles

Key points to remember

Basic rule (art. 10.1): adapt your speed to weather conditions and your field of visibility, and be able to stop before a foreseeable obstacle , the posted limit is a ceiling Wet road: braking distance multiplied by two ; safety distance increased from 2 to 3 seconds Snow or ice: safety distance of at least 4 seconds (133 m at 120 km/h) Fog: slow down gradually when entering the fog bank Dipped headlights mandatory as soon as visibility drops below approximately 200 m , day and night Rear fog light mandatory below approximately 100 m in fog or snowfall, and always in heavy rain; prohibited in other cases Front fog lights : only in fog, snowfall or heavy rain No danger sign announces fog, ice or snow: this is the A15 with additional panel Slow down before the bend, never during; never change tyre pressure according to weather

Congratulations!

First do the quiz for this lesson to validate your learning, then practise on the exam simulator and the MCQs . You have completed this entire course. Congratulations, now for the practical part!

BelgianLicenses

Theory without practice is forgotten: move on to the MCQs to durably anchor your learning.