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Highway Code · Rule 236

Highway Code Rule 236

Driving in adverse weather conditions (226 to 237). A legal requirement (MUST / MUST NOT).

  • Driving in adverse weather conditions
  • Legal requirement
  • OGL v3.0

What the rule says

Law · MUST

Rule 236 (Fog (rules 234 to 236)) You MUST NOT use front or rear fog lights unless visibility is seriously reduced (see Rule 226) as they dazzle other road users and can obscure your brake lights. You MUST switch them off when visibility improves. Law RVLR regs 25 & 27

Rule text reproduced verbatim from the official Highway Code (Crown copyright) under the Open Government Licence v3.0, see the attribution at the foot of this page.

In plain English

Stripped of the formal wording, Rule 236 comes down to one idea: rule 236 (Fog (rules 234 to 236)) You MUST NOT use front or rear fog lights unless visibility is seriously reduced (see Rule 226) as they dazzle other road users and can obscure your brake lights. Because it is written with “MUST” or “MUST NOT”, it carries the force of law, ignore it and you are committing an offence, not simply driving badly.

It belongs to the driving in adverse weather conditions part of the Code, the habits a confident, considerate driver builds until they are automatic. The aim is not to memorise the sentence word for word, but to understand the hazard it protects you from, so you apply it without having to think when it counts.

If you are learning, treat this rule as one piece of a connected set rather than an isolated fact. The related rules below sit in the same section and reinforce each other, reading them together is how the driving in adverse weather conditions part of the Code starts to feel like common sense rather than a list to revise.

Because this is a legal rule, the consequences of ignoring it reach beyond the test: a “MUST” or “MUST NOT” breach can mean a fixed penalty, points on your licence, or in serious cases prosecution. Either way, the safe move is to build the habit early, while a driving instructor can correct it, rather than relearning it under test pressure. That is exactly what the practice routes and coaching in the DriveRoutes app are designed to help with, turning the rules below into the way you naturally drive.

Why rule 236 matters on the road

Rain, fog, ice and low sun change how your car behaves and how far you can see. Adjusting early, before you actually need the extra space, is what keeps a tricky drive uneventful rather than dangerous.

Common faults examiners record

In the driving in adverse weather conditions part of the Code, the faults most often written on the marking sheet tend to be the same handful. Knowing them in advance is the quickest way to drive them out of your own habits:

  • Carrying too much speed for the visibility or grip.
  • Forgetting to use, or switch off, lights as conditions change.
  • Following too closely when stopping distances have grown.

On the day

Picture the road surface darkening with rain mid-test. Applying Rule 236 means easing your speed, lengthening your following distance and using lights appropriately, adjusting before the conditions force your hand rather than after.

Quick checklist

  • Match your speed to what you can actually see and feel.
  • Use the right lights for the conditions.
  • Leave a bigger gap whenever grip or visibility drops.

More from Driving in adverse weather conditions

Related Highway Code rules

Rule 236, your questions

Rule 236 (Fog (rules 234 to 236)) You MUST NOT use front or rear fog lights unless visibility is seriously reduced (see Rule 226) as they dazzle other road users and can obscure your brake lights. It is a legal requirement, it uses “MUST” or “MUST NOT”, so breaking it is a criminal offence that can mean a fine, penalty points, or disqualification.

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