Please refer to the term 'outermost' as the driving side and 'innermost' as the overtaking side, because right and left are swapped depending on the country.

Here is an example of a 3 lane roundabout

For a 3 lane roundabout with 2 lane entry, the outermost lane gets the benefit of choice. The outermost lane can choose either the middle lane or the outer lane. The innermost lane must enter into the inner lane. If there is a collision where the inner lane and outer lane tries to enter the middle lane, the inner lane will be fined

For a 3 lane roundabout with 2 lane exit, the outer lane must exit into the outer lane, the middle lane must exit into the inner lane, and the inner lane cannot exit. If there is a collision where the inner lane and middle lane tries to exit into the inner lane, the inner lane will be fined

In general, in order to enter a roundabout, you count from inside to outside and enter into your lane, any remaining lanes belong to the outermost lane. The road will never have more lanes on entry than lanes inside the roundabout

In order to exit a roundabout, you count from outside to inside and exit in your lane, any remaining lanes belong to the innermost lane. If there are more lanes inside the roundabout than lanes on exit, the lanes which have no corresponding exit do not have right of exit and cars on these lanes must change outwards before exiting the roundabout.

Please confirm if these rules are lawfully correct in countries


Where signage does not indicate otherwise

  • 2
    What did you find in the relevant driving rules in each country about this?
    – Traveller
    Commented Oct 9, 2023 at 8:12
  • 4
    In the UK, most large roundabouts (more than 2 lanes) will have arrows painted in the lanes. These will indicate which lanes may be used for which direction.
    – badjohn
    Commented Oct 9, 2023 at 8:13
  • 6
    While you do a pretty good try in describing the roundabout, a simple picture would be helpful. Find a pic on internet if you are not up to drawing one yourself.
    – Willeke
    Commented Oct 9, 2023 at 9:17
  • 1
    If you want to really see how it's done try this one in Bangkok (google.com/maps/@13.7567013,100.5012584,267m/…) inside a Tuk-Tuk. While I'm sure there are rules, I'm equally sure that no Tuk-Tuk driver gives a hoot. If that doesn't give you a heart attack nothing will :-)
    – Hilmar
    Commented Oct 9, 2023 at 14:01
  • 4
    I don't get the description at all: a diagram is very necessary. "For a 3 lane roundabout with 2 lane exit, the outer lane must exit into the outer lane". No, the outer lane of the roundabout exits to the inner lane of the exit road. In UK some drivers stay in the outer lane no matter which exit they are taking (which upsets the flow of traffic which generally moves out in a spiral as they approach their exit). For advice on the use of UK roundabouts, please see the Highway Code. Commented Oct 9, 2023 at 18:25

1 Answer 1


This is UK-specific.
I've reversed the OP's definitions of outer & inner as they're opposite to convention.
Outside/offside is the side the driver sits. Inside/nearside is the passenger's side. In the UK from left to right we have inner, centre/middle, outer lanes. Because 'outside' on a straight road & 'outside' on a roundabout can be counter-intuitively opposing, it's best to refer to nearside, centre and offside; left, middle and right, or number the lanes, starting on the left.

If the lanes are simply concentric, then the idea is that you move over one lane to your left at the end of each junction, before the next. Some roundabouts break the laning periodically to allow you do do this without crossing a white line. Some don't.
This is still common for two-lane roundabouts, less so for three-lane.

This seems to have got more problematic over the past couple of decades, and generally lane discipline has got worse. A smaller percentage of people seem to know how to do it properly.

One way to avoid this confusion in the UK was with the introduction of spiral roundabouts. On a spiral roundabout, if you start in the offside [3rd] lane to turn right [3rd exit], then without crossing any lane lines at all, by the time you get to the 3rd exit, you will have spiralled out & now be in the nearside [1st] lane (or occasionally middle, 2nd lane depending on the exit laning strategy).
These roundabouts also also tend to expand from 2 to 3 lanes as you approach the roundabout itself, to try prevent 'discussions', yet the exits are just 2-lane. See https://www.drivingcrawley.co.uk/blog/how-to-deal-with-spiral-roundabouts which also shows how the lane arrows are displayed.

BTW, no-one, no matter spiral or concentric, should be trying to exit from the 3rd lane - crossing two lanes to exit is going to get you dented. Even the middle lane isn't truly safe for that; you have to have your wits about you. Not all roundabouts are equal & sometimes the locals have different habits for different exits… no matter what the markings say. This is not exactly legal & not exactly safe, but it is exactly what happens.

Here's an idealistic drawing of a spiral roundabout. Note that lane 2 at each exit is allowed to turn off or continue. Lane 1 must exit.
These are the ones you need to be most careful of.

enter image description here

This what you need to watch out for. You're in blue, going straight over. The lanes give you the right to do this. The idiot in red jumps the left lane to go straight over too. It's his fault when you hit him, but both cars get dented just the same.

enter image description here

Don't do this. Don't cross lanes as you exit. Stay in the outside [offside] lane until clear of the junction & you can properly determine if someone is on your inside [nearside]. They could have come from the left as you exited & you may not have seen them.

enter image description here

This is a typical 2-lane roundabout. Note that if you enter from the bottom of the picture in the left lane, you can go straight, or turn left. Note also that someone coming from your right in the 2nd lane on the roundabout, is quite within their rights to cut across you and exit to the left-most junction.
It's their right of way, not yours, because you must give way to the right.

enter image description here

Just to complete the set - some roundabouts also have traffic lights, which means the normal give way rules don't apply. You follow the lights instead.
Some, however, only have peak period lights [rush hour] - so if the lights are off, the normal give way rules do apply.
A word of warning: You always give way to traffic already on the roundabout. However, if it's busy someone might flash or wave to let you in. Just because they let you in doesn't mean the guy coming through on the next lane did too. Ease gently out & make sure it's clear or that lane has also stopped to let you in.

Source - https://www.accord-driving-school.com/spiral-roundabouts

Note: most sat navs these days [including on mobile phones] have lane-assist, so you will get some [small] notice of which lane to start in on larger roundabouts.

Also note: 3 lanes isn't the maximum, nor 4 exits. There are also roundabouts that are part roundabout, part straight through the middle [cut-through]. They're quite rare but you need to be prepared. There's also the infamous 'magic roundabout' which is a large roundabout, surrounded by lots of mini-roundabouts… which scarily means you can travel either way round them. I only know of two in the whole country, Swindon & Hemel Hempstead, so if you're not going there, don't worry. This covers a good few of those types - https://www.passmefast.co.uk/roundabout-types

A clarification of the arrows you might see.
Because it's hard to indicate simply with an arrow that you have to go round to go right, the 'roundness' is ignored. Therefore an arrow pointing left is 'this junction'. One pointing straight is 'next junction' and one pointing right is 3rd [or higher] junction, keep going round.
This image is, 1. 'this junction', 2. 'next junction', 3. also 'next junction', or 'keep going round' [3rd junction or more].
The 'next junction' in this instance, you can exit from either the left or centre lanes. [The original left turn lane will have disappeared & a new right lane replaced it, so you've moved a lane to the left without crossing a line.]

enter image description here

Above all - if you keep your head, none of this is as bad as it looks.
I live near & regularly travel via four of the UK's most crash-prone roundabouts - all on London's A406, North Circular - & I haven't hit anything yet.


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