Roundabouts

UK roundabouts — Highway Code rules and lane discipline

Last reviewed against gov.uk on

Roundabouts generate more theory-test questions, more practical-test failures and more confused Reddit posts than any other UK road feature. The Highway Code covers them in five consecutive rules — 184 to 188 — plus the 2022 hierarchy update that explicitly stops drivers overtaking cyclists in their own lane. Every rule and the lane discipline that flows from it, below.

When reaching the roundabout you should give priority to traffic approaching from your right, unless directed otherwise by signs, road markings or traffic lights.
GOV.UK — Highway Code, Using the road (Rule 185)

Rule 184 — approach

On approaching a roundabout, apply the Mirrors – Signal – Manoeuvre (MSM) routine at every stage and decide as early as possible which exit you need to take. Look well ahead: the second or third sign on the approach usually shows lane allocation, and the first chance to slow safely is well before the give-way line.

Cancel your signal correctly. A signal that stays on when you don’t intend to turn is one of the most-cited examiner faults — and on the theory test it’s a familiar wrong-answer trap.

Rule 185 — priority

Give priority to traffic approaching from your right. The rule has one universal override: signs, road markings or traffic lights take precedence over the general right-of-way rule.

  • If the roundabout has traffic lights, treat the lights as you would at any junction.
  • If road markings direct otherwise (e.g. arrows pointing across), follow the markings even if it feels counter-intuitive.
  • If signs indicate otherwise (some larger junctions have non-standard priority), follow the signs.

“Give priority to traffic from your right” is the answer to the single most-asked roundabout question on the theory test — but only in the absence of signs, markings or lights.

Rule 186 — signals and lane choice

Rule 186 is the most-tested roundabout rule because the lane and signal differ for every exit. Use this matrix when the exit you want is …

UK roundabout signalling — Rule 186, with the common '12 o'clock' clock-face shorthand
Your exit Lane on approach Signal on approach On the roundabout Signal to leave
Left (first exit, before 12 o’clock) Left Left Keep left Continue signalling left
Straight ahead (around 12 o’clock) Left, unless signs direct otherwise None on approach Keep left Left signal after the exit before yours
Right (past 12 o’clock) Right Right Keep right until you need to change lane to exit Left signal after the exit before yours
Full circle / U-turn Right Right Stay right until past 12 o’clock Left signal after the exit before yours

Rule 186 itself uses the phrasings "first exit to the left" for left turns, "any intermediate exit" for the straight-on or middle case, and "an exit to the right or going full circle" for right turns — with the general advice to take "the most appropriate lane on approach and through it" when there are more lanes. The 12 o'clock framing is a memory aid that maps onto those three cases.

Rule 187 — extra care for pedestrians, motorcyclists and long vehicles

Rule 187 lists the categories of road user that need extra care at every roundabout:

  • Pedestrians who may be crossing the approach and exit roads. Give them time.
  • Traffic crossing in front of you on the roundabout, especially vehicles intending to leave by the next exit, and traffic which may be straddling lanes or positioned incorrectly.
  • Motorcyclists — small profile, easy to miss in a quick mirror check.
  • Long vehicles (including those towing trailers) may straddle two lanes because of their turning circle. Give them room. They may signal differently from a car because of the path they need to follow.

Rule 186 — cyclists, horse riders and horse-drawn vehicles on the roundabout

Rule 186 (final paragraph, added in the January 2022 update) is the one that often catches drivers out: “Cyclists, horse riders and horse drawn vehicles may stay in the left-hand lane when they intend to continue across or around the roundabout and should signal right to show you they are not leaving the roundabout.” Drivers must not assume a cyclist in the left-hand lane is taking the next exit — look for the right-arm signal as the cue that the cyclist is staying on the roundabout. Rule 186 also explicitly says “do not attempt to overtake them within their lane.” See the 2022 H3 update below.

Rule 188 — mini-roundabouts

Mini-roundabouts are approached and treated like normal roundabouts. Two specific rules apply:

All vehicles MUST pass round the central markings except large vehicles which are physically incapable of doing so.
GOV.UK — Highway Code, Rule 188

The “physically incapable” exemption is narrow — it covers long lorries and articulated vehicles, not regular cars or vans. Driving straight over the painted central island in a normal car is an offence.

Avoid making a U-turn at a mini-roundabout if possible. Drivers behind you have very little time to see what you’re doing.

Sequential (double) mini-roundabouts

Where two mini-roundabouts sit close together, treat each one separately. Apply Rule 185 (give way to the right) at the first; once you’ve cleared it, repeat the routine for the second. People who try to read both junctions as one feature get it wrong on test and in real life — including signalling once for the combined manoeuvre, which is incorrect.

Multi-lane and spiral roundabouts

Larger roundabouts (often called “magic” or spiral roundabouts) have lane markings that spiral outwards as you cross the junction. The rule is: follow your lane — don’t change lanes on the roundabout itself unless arrows direct otherwise. The painted arrows tell you which exit each lane allows; an early lane choice is what protects you.

The 2022 hierarchy change — Rule H3 + Rule 186 update

The Hierarchy of Road Users introduced on 29 January 2022 explicitly applies at roundabouts. Drivers must not attempt to overtake a cyclist within that cyclist’s lane on a roundabout, even if there appears to be space. The cyclist may be staying in the left lane on the way to taking the third exit — exactly as the cyclists’ rule allows. See the full 2022 changes summary.

Common test questions and the answers

“Who has priority at a mini-roundabout?”

Traffic from the right has priority — the same as a normal roundabout. The smaller scale doesn’t change Rule 185.

“I’m taking the third exit. When do I signal left?”

After you pass the exit immediately before yours. Signal too early and the driver behind thinks you’re leaving at the wrong exit; signal too late and the driver behind has no warning.

“The right lane is empty and the left lane is busy. Can I take the second (straight-on) exit from the right lane?”

Only if signs or arrows explicitly allow it. The default for a straight-ahead exit is the left lane. Some larger roundabouts mark the right lane as straight-on permitted (look for arrows on approach) — but assume left-lane unless the markings say otherwise.

“There’s a cyclist on the roundabout in the left lane. I want to take the second exit. What should I do?”

Wait behind them rather than overtake. The cyclist may be going to the third or fourth exit in the left lane, which the Code expressly permits. The 2022 hierarchy makes the overtake explicitly wrong.

Sources

Highway Code excerpts are reproduced under the Open Government Licence v3.0.