Further theory lessons

Drive in darkness, rain and fog

Reason from the conditions, not from a memorised answer. Read the scene, choose, then open the explanation. The drawing is illustrative; the written conditions control the question.

Speed, visibility and stopping space belong together. Keep windows clear, choose the proper lights and reduce speed before the visible clear distance becomes shorter than your stopping distance.

Under the current Belgian rule, fitted rear fog lights are used in fog or snow reducing visibility below about 100 m, and also in heavy rain. Do not transfer the fog visibility threshold to heavy rain.

Turn rear fog lights off when the conditions requiring them end. High beam can dazzle others and reflect in fog; illumination does not replace safe speed, following distance or observation.

Regulatory source ↗

Reviewed 2026-11-06

Apply the lesson · 1

Question 1 · Advanced scenarios

Heavy rain is falling and visibility is about 150 m. Rear fog lights are fitted. Does being above 100 m alone remove their use requirement?

Yes; rear fog lights are only required below 100 m in any weather.
Yes; main beam replaces rear fog lights in rain.
No; heavy rain is itself a condition in the current rule.

Show the answer and explanation

Correct answer: C

Speed, visibility and stopping space belong together. Keep windows clear, choose the proper lights and reduce speed before the visible clear distance becomes shorter than your stopping distance. Under the current Belgian rule, fitted rear fog lights are used in fog or snow reducing visibility below about 100 m, and also in heavy rain. Do not transfer the fog visibility threshold to heavy rain.

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