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Highway Code

Highway Code, Light signals controlling traffic

Light signals controlling traffic. A legal requirement (MUST / MUST NOT).

  • Light signals controlling traffic
  • Legal requirement
  • OGL v3.0

What the rule says

Law · MUST

Download ‘Light signals controlling traffic’ (PDF, 80KB)

Traffic light signals

RED means ‘Stop’. Wait behind the stop line on the carriageway RED AND AMBER also means ‘Stop’. Do not pass through or start until GREEN shows GREEN means you may go on if the way is clear. Take special care if you intend to turn left or right and give way to pedestrians who are crossing AMBER means ‘Stop’ at the stop line. You may go on only if the AMBER appears after you have crossed the stop line or are so close to it that to pull up might cause an accident A GREEN ARROW may be provided in addition to the full green signal if movement in a certain direction is allowed before or after the full green phase. If the way is clear you may go but only in the direction shown by the arrow. You may do this whatever other lights may be showing. White light signals may be provided for trams

Flashing red lights

Alternately flashing red lights mean YOU MUST STOP At level crossings, lifting bridges, airfields, fire stations, etc.

Motorway signals

These signals are also used on other high-speed roads. You MUST NOT proceed further in this lane Change lane Reduced visibility ahead Lane ahead closed Temporary maximum speed advised and information message You MUST NOT enter or proceed in the left lane, temporary mandatory maximum speed limit and information message Temporary maximum speed advised End of restriction

Lane control signals

Green arrow - lane available to traffic facing the sign Red crosses - lane closed to traffic facing the sign White diagonal arrow - change lanes in direction shown

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, this guidance comes down to one idea: download ‘Light signals controlling traffic’ (PDF, 80KB) RED means ‘Stop’. 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 light signals controlling traffic 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 light signals controlling traffic 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 this rule matters on the road

Signs, signals and markings are the shared language of the road. Reading them accurately and signalling clearly is how drivers coordinate without ever speaking, miss the message and the coordination breaks down.

Common faults examiners record

In the light signals controlling traffic 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:

  • Signalling too late, too early, or when no signal is needed.
  • Missing a sign or road marking and acting on the wrong information.
  • Failing to cancel a signal after a manoeuvre.

On the day

Imagine a sign appearing on the approach to a junction. Applying Highway Code, Light signals controlling traffic means reading it early, acting on it in good time, lane, speed, signal, and cancelling any signal once the manoeuvre is complete. The examiner notes whether you respond to the information or miss it.

Quick checklist

  • Read signs and markings early and act in good time.
  • Signal clearly, only when it helps someone.
  • Cancel the signal once the manoeuvre is done.

Highway Code, Light signals controlling traffic, your questions

Download ‘Light signals controlling traffic’ (PDF, 80KB) RED means ‘Stop’. 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.

DriveRoutes is an independent study aid and is not affiliated with, endorsed by, or connected to the Driver and Vehicle Standards Agency (DVSA).