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Highway Code · Rule 112

Highway Code Rule 112

General rules, techniques and advice for all drivers and riders (103 to 158). A legal requirement (MUST / MUST NOT).

  • General rules, techniques and advice for all drivers and riders
  • Legal requirement
  • OGL v3.0

What the rule says

Law · MUST

Rule 112 (Other stopping procedures (rules 107 to 112)) The horn. Use only while your vehicle is moving and you need to warn other road users of your presence. Never sound your horn aggressively. You MUST NOT use your horn

  • while stationary on the road
  • when driving in a built-up area between the hours of 11.30 pm and 7.00 am except when another road user poses a danger. Law CUR reg 99

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 112 comes down to one idea: rule 112 (Other stopping procedures (rules 107 to 112)) The horn. 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 general rules, techniques and advice for all drivers and riders 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 general rules, techniques and advice for all drivers and riders 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 112 matters on the road

These are the foundations every other skill builds on. Solid mirror work, sensible speed and good lighting habits quietly prevent the situations the rest of the Code has to deal with.

Common faults examiners record

In the general rules, techniques and advice for all drivers and riders 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:

  • Skipping or rushing mirror checks before a manoeuvre.
  • Carrying an unsuitable speed for the road and conditions.
  • Reacting late because hazards were spotted too close.

On the day

On the day, applying Rule 112 is about doing the safe, deliberate thing slightly earlier than feels necessary: read the situation in good time, observe fully, and act smoothly. The examiner is looking for planned driving, not perfection, and good habits formed in lessons carry you through.

Quick checklist

  • Read the situation early and plan your response.
  • Observe fully before you commit to anything.
  • Keep your speed suitable for the road and conditions.

More from General rules, techniques and advice for all drivers and riders

Related Highway Code rules

Rule 112, your questions

Rule 112 (Other stopping procedures (rules 107 to 112)) The horn. 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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