Higher-speed roads

Dual carriageways

Lesson breakdown

Sub-skills

Practical test

Why it matters

Dual carriageways test higher-speed judgement, mirror and blind-spot use, lane discipline and forward planning. Poor lane discipline or a late, forced lane change can be recorded as a fault, and more seriously if it makes another driver react.

What to look out for

Keep left, right lane to pass

On a two-lane dual carriageway your normal position is the left lane. The right lane is for overtaking or turning right, not for cruising.

The slip road does the work

Joining and leaving both happen on the slip road - build speed on it when joining, lose speed on it when leaving, so the main carriageway stays smooth.

Key steps

  1. 1 Join by building speed on the slip road to match the traffic already on the carriageway, checking mirrors and your blind spot before you merge - you give way to them, not the other way round.
  2. 2 Keep to the left-hand lane, using the right lane only to overtake or turn right, and return left once you've finished.
  3. 3 Before any lane change, check your mirrors and take a quick sideways glance so you don't make anyone behind change speed or course.
  4. 4 Plan your exit early from the direction signs and countdown markers, and move into the left lane in good time rather than changing late.
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Common mistakes

Joining too slowly

Use the slip road to reach carriageway speed so you fit into a gap, rather than making faster traffic slow for you.

Sitting in the right lane

The right lane is for overtaking or turning right - return left as soon as it's safe once you've passed.

Changing lanes late

Read the signs and countdown markers early so your lane is settled before the exit, not snatched at the last moment.

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Highway Code

This lesson is a revision aid, not a replacement for The Highway Code.

Rule 137

On a two-lane dual carriageway, stay in the left-hand lane and use the right-hand lane only for overtaking or turning right, returning to the left when you've finished.

Read on GOV.UK

Rule 133

Before changing lane, use your mirrors and if necessary take a quick sideways glance, so you don't force another road user to change speed or course.

Read on GOV.UK
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Keep going