Rule 133 (Multi-lane carriageways (rules 133 to 143)) If you need to change lane, first use your mirrors and if necessary take a quick sideways glance to make sure you will not force another road user to change course or speed. When it is safe to do so, signal to indicate your intentions to other road users and when clear, move over.
Highway Code · Rule 133
Highway Code Rule 133
General rules, techniques and advice for all drivers and riders (103 to 158). Advisory guidance you are expected to follow.
- General rules, techniques and advice for all drivers and riders
- Advisory rule
- OGL v3.0
What the rule says
AdvisoryRule 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 133 comes down to one idea: rule 133 (Multi-lane carriageways (rules 133 to 143)) If you need to change lane, first use your mirrors and if necessary take a quick sideways glance to make sure you will not force another road use… It is advice rather than law, but examiners and the courts still treat it as the expected standard of safe driving.
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 advisory rather than legal, no one will fine you for the rule alone, but ignoring it can still count against you in a careless-driving case, and it will cost you faults on the test. 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 133 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 133 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 132Highway Code Rule 132Rule 132 (Lines and lane markings on the road (rules 127 to 132)) Reflective road studs may be used with white lines.
- Rule 134Highway Code Rule 134Rule 134 (Multi-lane carriageways (rules 133 to 143)) You should follow the signs and road markings and get into the lane as directed.
- Rule 131Highway Code Rule 131Rule 131 (Lines and lane markings on the road (rules 127 to 132)) Lane dividers.
- Rule 135Highway Code Rule 135Rule 135 (Multi-lane carriageways (rules 133 to 143)) Where a single carriageway has three lanes and the road markings or signs do not give priority to traffic in either direction - use the middle la…
- Rule 130Highway Code Rule 130Rule 130 (Lines and lane markings on the road (rules 127 to 132)) Areas of white diagonal stripes or chevrons painted on the road.
- Rule 136Highway Code Rule 136Rule 136 (Multi-lane carriageways (rules 133 to 143)) Where a single carriageway has four or more lanes, use only the lanes that signs or markings indicate.
Rule 133, your questions
Rule 133 (Multi-lane carriageways (rules 133 to 143)) If you need to change lane, first use your mirrors and if necessary take a quick sideways glance to make sure you will not force another road use… It is advisory guidance rather than law, but you are still expected to follow it and an examiner can mark a fault if you do not.
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