What does Highway Code Rule 172 say?

Rule 172 (Road junctions (rules 170 to 183)) The approach to a junction may have a ‘Give Way’ sign or a triangle marked on the road. 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.

Is Rule 172 a legal requirement?

Yes. Rule 172 uses “MUST” or “MUST NOT”, which marks it as backed by law. Disobeying it is a criminal offence and can lead to a fine, penalty points on your licence, or disqualification.

How is Rule 172 tested on the driving test?

This sits at the heart of the practical test. Examiners watch your road positioning, lane discipline, junction approach and your Mirror–Signal–Manoeuvre routine on almost every part of the drive, getting this section right is the difference between a clean sheet and avoidable faults.

What are the common mistakes related to Rule 172?

The faults examiners most often record around this part of the Code are: poor lane discipline, drifting wide on approach or sitting in the wrong lane through a junction; late or missing observation before changing position, especially the blind-spot check; hesitation at junctions that holds up traffic, or the opposite, moving off without a safe gap. Rehearsing the safe habit during lessons is the most reliable way to avoid them.

Highway Code · Rule 172

Highway Code Rule 172

Using the road (159 to 203). A legal requirement (MUST / MUST NOT).

Using the road
Legal requirement
OGL v3.0

What the rule says

Law · MUST

Rule 172 (Road junctions (rules 170 to 183)) The approach to a junction may have a ‘Give Way’ sign or a triangle marked on the road. You MUST give way to traffic on the main road when emerging from a junction with broken white lines across the road. Laws RTA 1988 sect 36 & TSRGD schedule 9 parts 7 and 8

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 172 comes down to one idea: rule 172 (Road junctions (rules 170 to 183)) The approach to a junction may have a ‘Give Way’ sign or a triangle marked on the road. 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 using the road 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 using the road 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 172 matters on the road

Most collisions happen at junctions, on bends and during overtakes, exactly the situations this part of the Code governs. Following it makes your intentions predictable to everyone around you, which is the single biggest factor in avoiding the conflicts that lead to crashes.

Common faults examiners record

In the using the road 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:

Poor lane discipline, drifting wide on approach or sitting in the wrong lane through a junction.
Late or missing observation before changing position, especially the blind-spot check.
Hesitation at junctions that holds up traffic, or the opposite, moving off without a safe gap.

On the day

Picture a busy junction on your test route. Applying Rule 172 looks like this: you check your mirrors early, decide your position and signal in good time, settle into the correct lane well before the line, and make a final effective observation before you commit. Done smoothly, the examiner sees a planned, unhurried manoeuvre rather than a last-second reaction.

Quick checklist

Mirrors first, then signal, then manoeuvre, every time.
Decide your lane and position early, not at the line.
Make a final effective observation before you commit.

Related Highway Code rules

Rule 172, your questions

: Rule 172 (Road junctions (rules 170 to 183)) The approach to a junction may have a ‘Give Way’ sign or a triangle marked on the road. 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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