Roundabout Rules UK: Lanes, Signals and the Mistakes That Cause Claims

The junction Britain runs on

The UK operates tens of thousands of roundabouts, and they work brilliantly — right up until two drivers hold different theories about lane discipline. The rules are Highway Code Rules 184–190; the crashes are almost all lane-and-signal misunderstandings; and the insurance outcomes follow patterns worth knowing before you're in one.

The core rules, restated properly

Priority: give way to traffic already on the roundabout, approaching from your right — unless signs, signals or markings say otherwise. Priority is to the circulating vehicle, not to speed of arrival, and give way means adjusting or stopping, not merging into a gap that requires the other car to brake.

Approach and lane choice (the 12 o'clock method): picture the roundabout as a clock, entering at 6.

• Left turns and straight-ahead (exits before/at 12): approach in the left lane unless markings direct otherwise.
• Exits past 12 (right turns, U-turns): approach in the right lane, circulate, and exit after signalling.
• Markings override the clock — spiral-marked and multi-lane roundabouts assign exits to lanes explicitly, and the painted arrow beats the folklore every time.

Signalling that communicates:

• Left turn: signal left on approach, hold it through exit.
• Straight ahead: no signal on approach; signal left after passing the exit before yours. This is the one drivers skip, and it's the signal that lets the queue at the next entry actually pull out.
• Right/past 12: signal right on approach and while circulating; switch to a left signal after the exit before yours.

Where the collisions actually happen

• The lane-straddle spiral exit: a driver circulates in the right lane then exits across the left lane's path. On multi-lane roundabouts, exit from the lane you're in — if you've missed your exit's lane, go around again; the extra fifteen seconds is the cheapest insurance available.
• The hesitant merge: entering into a circulating car's path "because they were slow." Priority doesn't expire with your patience; the entering driver is presumptively at fault in entry-collision claims, and insurers settle accordingly.
• The phantom signal: trusting an approaching car's left signal and pulling out — into a driver who forgot the indicator was on. The Code's standard is to rely on position and speed, not signals alone; claims where you "trusted the indicator" split fault uncomfortably often.
• Mini-roundabouts: all the same rules at 10% of the size. You must pass around the centre marking (Rule 188 — only vehicles physically too large may cross it), signalling is compressed but still expected, and U-turns are lawful but hazardous. The white disc is not decoration, and treating it as one is a classic careless-driving fixed penalty.

The users the Code tells you to expect

Cyclists and horse riders may lawfully stay in the left lane while travelling all the way around — the 2022 Code explicitly instructs drivers to give them extra room and never cross their path. Long vehicles straddle lanes by necessity; the correct response to an HGV's roundabout geometry is space, not the gap down its inside.

The questions drivers actually ask

Who's at fault in a roundabout collision? Patterns, not guarantees: entering vs circulating — entering driver; lane-change/straddle exits — the straddler; rear-end at the give-way line — the follower (the classic "they pulled out then stopped" claim usually lands on the car behind). Dash cams resolve what diagrams argue.

Do I signal at every tiny roundabout? Where there's anyone to inform — including pedestrians — yes, as far as practical. Empty roundabout at dawn: the Code's "if necessary" standard applies.

Turbo/spiral roundabouts confuse me — the fix? Read the overhead and painted arrows before the give-way line, commit to the lane, and follow your lane's spiral out. The design removes lane-change decisions entirely if you enter correctly — the skill is all in the approach.

What about traffic-light roundabouts? Signalised roundabouts suspend give-way-to-the-right wherever lights control an entry or internal node — the signal is the law while it operates, and part-time signals revert to normal priority when off. Lane discipline rules continue unchanged beneath the lights, which is why the painted arrows still decide most outcomes there.

• Give way to circulating traffic from the right; markings override the default left-for-12, right-for-past-12 approach rule
• Signal left after the exit before yours — the forgotten signal that makes roundabouts flow
• Never exit across another lane: missed your lane, go around again
• Mini-roundabout centre discs must be driven around, not over, unless your vehicle physically cannot
• Entering-vehicle fault presumptions and dash-cam evidence decide most roundabout claims

Key takeaways

• Give way to circulating traffic from the right; markings override the default left-for-12, right-for-past-12 approach rule
• Signal left after the exit before yours — the forgotten signal that makes roundabouts flow
• Never exit across another lane: missed your lane, go around again
• Mini-roundabout centre discs must be driven around, not over, unless your vehicle physically cannot
• Entering-vehicle fault presumptions and dash-cam evidence decide most roundabout claims