Once upon a time I was told that you indicate continuing on the roundabout when doing a 180-270 on a 4 way, but then that was abandoned, Till today I do that to let other drivers know what my intentions are, thusly if I drive on the inside, the one who’s planning a 90 can anticipate. As for indicating the exit, I do, others… OFL.
I’m sure this is true - in Nederland we would simply call that a roundabout. Unless it’s so small that, say, a funeral car can’t even make the required turn without touching the circle. If you can’t really circle around, we would not consider it a roundabout. Still, a raised centre circle helps as a traffic calming device.
Some are so small a normal car cannot turn right without without touching or crossing the circle.
They are often used at former cross roads or T junctions to equalise priority, where traffic flow on the priority route can effectively block traffic leaving side roads
The roundabout comes from the system of priority. Roundabout being named after the fairground ride, if roundabouts had originated in the US they would be called carrousels.
I was told the signalling is not a legal thing? In Nederland we are advised to signal only when exiting the roundabout, not when entering, but many drivers signal at entry, and then to indicate where you want to go (right is next exit, left is to the -most often- third exit), not the actual movement which is alway a right turn for us. I think that matches “signaling as you would at a standard junction”.
That is how most drivers in the UK do it, same in France although many french drivers take roundabouts much slower the British drivers do, but they aren’t a new idea for us.
Maybe travel and experience driving in different countries?
Usual approach in new countries is to be cautious and observe how the locals do it. The first one for a British driver in France is to take roundabouts slower.
I don’t think that geometry should be a deciding factor of chosing one tagging or another. You can always chose not to divide roads on island (and just map the island as traffic island). But honestly, I don’t think that separating roads looks that bad when the mini roundabouts are mapped as nodes.
What we should think is the function of those. Are mini roudabouts closer to normal junctions or to roundabouts? Should the driver get a command “Take 3rd exit” or “Turn left” when arriving to those?
Also, weirdly the topic was “taken over” by magic roundabouts. They are interesting and complicated, but there are not common. Like, how many magic roundabouts are there in the world? 10?
Well. if anything, this discussion shows that there are mini_roundabouts which are like disguised regular junctions, then there are mini_roundabouts which are actually two-lane roundabouts without the centerpiece.
So to the question “are they A or are they B” I can only answer: some are more like A and some are more like B. If you decide to map the B’s with a junction=roundabout ring and one way per separated carriageway, and the A’s with highway=junction nodes, you’re only concern is with the edge cases. My answer: let the mappers decide. Maybe by preference, maybe convention, maybe other considerations. Maybe the first mapper simply puts a node, the second just turns it into a ring, and the third has more time to spare and creates a roundabout with flares, turn restrictions and nice fluent bus relations.
My turning point would be when at least one of the roads physically splits into separated approach and exit lane. That would almost certainly mean that there is enough room for a true circular movement, which makes it a roundabout (provided the signs and markings are there).
Peter Elderson
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Picking one with islands which I am familiar with and remember when it was a cross roads.
https://mapillary.com/map/im/413175356874268
Whilst it is big enough for a car to avoid touching the paint. There is no way that the double deckers, which turn there can avoid it.
Danke @trigpoint und sorry, dass ich heute auf Deutsch antworte. Ich hoffe der translate-button macht einen guten Job.
Danke nochmals - das sind die mini-roundabouts über die wir hier diskutieren sollten. Nicht über magic-roundabouts, dass sind ganz besondere Spezialfälle. Dieser ovale mini-roundabout hat einen Außendurchmesser zwischen 20 und 25 Meter - das ist groß genug, dass man ihn als roundabout zeichnen könnte. Aber zu klein, dass ein großer LKW mit Anhänger den Kreis zu 3/4 durchfahren kann, ohne die Mittelinsel zu überfahren - deshalb ist die Mittelinsel baulich so gestaltet, dass sie im Ausnahmefall auch überfahren werden kann.
Dieser Kreisverkehr ist ein mini-roundabout, weil der Verkehr im Kreis Vorfahrt hat, die Mittelinsel überfahrbar ist und speziell in GB als mini-roundabout beschildert ist. Derzeit gibt es in OSM faktisch nur eine Möglichkeit, diese Kriterien abzubilden: als Punkt mit highway=mini_roundabout.
Wenn man diese Kreisverkehr detaillierter mappen möchte, insbesondere die Ein- und Ausfahrten der Dominion Road, bekommt man geometrisch seltsame Gebilde. Wenn man den mini-roundabout dagegen als Kreis (oder Oval) zeichnet und mit junction=roundabout taggt, kann man auch die Ein- und Ausfahrten exakt abbilden, verliert aber die Information, dass die Mittelinsel überfahrbar ist, denn dies kann durch einen kreisförmigen way nicht abgebildet werden.
Offensichtlich werden auch in GB, wo der mini_roundabout erfunden wurde, die mini_roundabouts immer größer (ich habe gelesen: bis zu einem Außendurchmesser von 28 m). Es besteht auch in GB zunehmend Bedarf, die größeren mini-roundabouts nicht mehr nur als Punkt, sondern als kreisförmigen way abzubilden - aber auch die Information darüber in der Datenbank zu haben, dass die Mittelinsel überfahrbar ist (und speziell in GB, dass der Kreisverkehr ein mini-roundabout ist, weil er so beschildert ist).
Wir haben daher im deutschen Forum nach der dritten oder vierten ewig langen Diskussion den key central_island:traversable entwickelt, um diese Problem zu lösen.
translated:
Thanks @trigpoint and sorry for replying in German today. I hope the translate-button does a good job.
Thanks again - these are the mini-roundabouts we should be discussing here. Not about magic-roundabouts, those are very special cases. This oval mini-roundabout has an outer diameter of between 20 and 25 metres - that’s big enough that you could draw it as a roundabout. But it is too small for a large lorry with a trailer to drive 3/4 of the way through the roundabout without driving over the central island - which is why the central island is structurally designed in such a way that it can also be driven over in exceptional cases.
This roundabout is a mini-roundabout because traffic has the right of way in the circle, the central island can be driven over and is specifically signposted in GB as a mini-roundabout. Currently, there is effectively only one way to map these criteria in OSM: as a point with highway=mini_roundabout.
If you want to map these roundabouts in more detail, especially the entrances and exits of Dominion Road, you get geometrically strange shapes. If, on the other hand, you draw the mini-roundabout as a circle (or oval) and tag it with junction=roundabout, you can also map the entrances and exits exactly, but you lose the information that the central island can be driven over, because this cannot be mapped by a circular way.
Obviously, also in GB, where the mini_roundabout was invented, the mini_roundabouts are getting bigger and bigger (I read: up to an outer diameter of 28 m).
There is also an increasing need in GB to map the larger mini-roundabouts not only as a point but as a circular way - but also to have the information in the database that the central island can be crossed (and especially in GB that the roundabout is a mini-roundabout because it is signposted that way).
We have therefore developed the key central_island:traversable in the German forum after the third or fourth eternally long discussion to solve this problem.
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That solves the issue for me. We would still need a “non-node” version of mini roundabout, and mappers would chose which version match in a specific case. We only need to make sure to clearly put in a description of the tag, that the difference is a FUNCTION not GEOMETRY.
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Where are the other rules? In highway code rule 188 I only find half a sentence:
Remember, there is … less time to signal.
In my opinion, this is not a different rule, but only a reference to the fact that the left-hand signal is often not given and that you should therefore be careful.
Or in other words:
You will find that when driving around mini-roundabouts there is less room to manoeuvre and less time to signal, so take extra care.
@Peter_Elderson I was recently on holiday in the Netherlands for a week. I think your country is just great!
Of course I had to drive a lot to visit this and that. I saw many roundabouts in North Holland, bigger and smaller ones and lots of turbo roundabouts. But I didn’t see any mini-roundabouts! I don’t know if there are any mini-roundabouts in the Netherlands.
But I have often seen such circles, not coloured but paved differently, sometimes slightly elevated.
https://www.mapillary.com/app/?pKey=974340876710211
These are indeed not mini-roundabouts. They are, as you wrote, rather traffic calming measures or simply indications of junctions with the same priority (right-hand-priority) or simple decoration.
In the countryside we do have junctions similar to small mini-roundabouts, often three-road-triangular junction areas where there is no through direction so to go on cars will aways make a slight turn, but most are either turned into true roundabouts (with at least signpoles in the centre island, and too large vehicles are banned from the approaching roads), or just the visual warning circle / raised central dot / no centre at all.
Thinking the other way around: if the centre must be kept free for oversized vehicles, the junction cannot be a roundabout. Either make more room, or forget the roundabout, junction constructor people!
For priority it does not legally matter if it’s a roundabout or not. Priority in NL always has to be signed separately by traffic signs and shark’s teeth markings. The roundabout sign legally means: oneway circular movement, nothing else. All other things need to be signed or marked. As in other countries, many other rules of conduct are flying all around the place, but they are not laws, and only enforcable under the general rule of “not endangering anybody”.
I understand that in the Netherlands the round blue sign “roundabout” is on the central island and therefore there can be no mini-roundabouts with a sign “roundabout”.
But: the sign “roundabout” is not a prerequisite for a roundabout to be a roundabout, seen worldwide. The British, for example, only use this round blue sign for mini-roundabouts.
OSM distinguishes:
Circular traffic routing without right of way in the circle: junction=circular
Roundabouts with right of way in a circle: junction=roundabout (how the right of way is regulated and signposted is secondary).
Both of the above have a central island that cannot be crossed.
Mini roundabouts have right of way in a circle and a centre island that can be driven over.
And then there are many intersections that look like roundabouts but are not roundabouts, not even mini-roundabouts. These are traffic calming measures or turning loops or sometimes simply a decorative design.
I once used overpass-turbo to search for mini roundabouts in the Netherlands. As expected, most of them are not mini-roundabouts. There are trees in the middle (not passable); there are circles painted on them, but no shark’s teeth or right of way signs; and one or two just look pretty …
You could clean all that up, they’re not mini-circles!
Of course, I can’t look at all of them. But I have found one (unfortunately without a mapillary) which, according to the aerial photo, is very probably a mini roundabout and very close to the British original, except that this one goes anti-clockwise.
But the approaches have shark’s teeth, the crossable centre is made of white circles and the direction of travel is marked with arrows on the ground and the diameter is only about 14-15m:
Node: 47131877 | OpenStreetMap
And to the northwest is another mini roundabout.
And yes, you can see from the aerial photo that drivers do not obey the rule of driving in circles, even though they could. But that doesn’t matter, cyclists also sometimes ride on the footpath even though they are not allowed to, yet the footpath does not become a cycle path 
And it should be possible to map such traversable mini-circle junctions, which are sometimes not so mini anymore, both as a point with highway=mini_roundabout and as a way. How we tag the latter without losing the drive-over centre island in the data is the subject of discussion.
edit:
This is also a mini roundabout:
No painted, but slightly raised central island, can be driven over.
No round blue sign “Roundabout”, but traffic on the circular lane always has right of way.
The fact that you have to drive anti-clockwise probably only results from the right-hand driving requirement.
OpenStreetMap
First off the UK Highway Code is simplified guidance that can be used in court, and is often based on actual laws and guidance found in more authoritative documents. (eg The Traffic Signs Regulations and General Directions 2016) or publications such as “Mini roundabouts: good practice guidance”.
To engage specifically with the guidance for signalling. It best to state that a standard roundabout has different signalling requirements, but a mini-roundabout doesn’t. As well as standard entry signaling, you always signal left when leaving a standard roundabout (drive on left). Due to the small size of mini-roundabouts you don’t signal left when leaving the mini-roundabout (unless it’s the first exit). Hard to describe in writing, but if you look at the image with Rule 185, or the gif below.
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Nicely found! Yes, it resembles a mini-roundabout. And tagging it as such conveys the priority rule. Which on the way is only conveyed by the shark’s teeth. Otherwise you would have to add a full three give_way nodes. So, I don’t think it’s necesaary, but I do think it’s correct!
It’s near endearing how they have tried to create a circular lane on the inside of the cycle lane, leaving a circular ‘lane’ where not even IJsbrand Chardon could manage to stay in lane. I bet 90% of the cyclists would cross over the center dot, which is hardly visible any more!
In contrast, this one connects four ways, it has a raised centre island, the circular lane is manageabe for most cars and vans, but the centre will be crossed over by buses and trucks, so the centre circle can not contain poles and signs.
Still, this is a roundabout, because all roads have paint-separated approach and exit lanes, and the approaches (which curve toward the circular lane) all have the roundabout sign, combined with the give_way sign. So it should be mapped as a regular small roundabout.
UK legalities
Could you point to the law that says there are any requirements to indicate at all? It is my understanding that there is no law on the statute books that says one must indicate, under any specific circumstance.
I believe (and may well be wrong) the “requirements” you mention are actually all guidance as laid out in the highway code.
Of course, as has been discussed in this thread, although the rules in the highway code are not directly enforceable (unless they use a MUST/MUST NOT as these are covered by law) they can be used as contributing factors for prosecution under other laws (e.g., driving without due care and attention/dangerous driving).
Having said all of that… it doesn’t really matter!
The legalities are for the driver not the mapper. We should just make sure it’s tagged correctly (e.g., the proposed junction=mini-roundabout).
edit: hide UK legalities to keep thread on-topic.
The UK Highway code has a large number of “should” or guidance, that are not directly mentioned in law/legislation. This results in a huge number of people incorrectly believing they are not enforceable. If the “should” or guidance involves Driving activities, they ARE enforceable.
Could you point to the law that says there are any requirements to indicate at all? It is my understanding that there is no law on the statute books that says one must indicate, under any specific circumstance.
The Road Traffic Act 1988, contains the offences of “Dangerous Driving” and “Careless, and inconsiderate, driving”.
When deciding what actions amount to the above, the “should” or guidance information are considered the default, or primary, examples of what constitutes these offences.
For not signalling you should be charged with “Careless, and inconsiderate, driving” under the Road Traffic Act 1988. But you could be charged with “Dangerous Driving” if there was clear evidence of likely harm from the action.
It’s notable and worrying that so many UK road users believe the “shoulds” in the Highway Code are not enforceable. They’re simply wrong about this. The UK Highway Code also has a list of Do Not, which are also considered the default examples of actions that are charged for offences such as Dangerous Parking.
Coincidentally I am about to submit a video to the police of a driver ignoring one of the “shoulds” in the Highway Code. Rule 163 states a driver should leave 1.5m of space when overtaking a bicycle. I was passed by a van that left 0.5m and have a video of it. I will shortly submit the video to the police who will almost certainly charge the driver with “Careless, and inconsiderate, driving” due to ignoring the “should” in Rule 163.
Thanks JassKurn, hiding most of my reply to your (interesting!) response in details to keep the thread tidy.
UK legalities
Hiding this, as we’re veering (pun intended) off topic here.
Is this a legally held opinion or your own? (Sorry, no idea what your background is.) Other sources disagree with you [e.g. 1]:
Breach of the Highway Code is often a good indicator of carelessness, but it doesn’t establish guilt in itself.
It seems more like “could” for both offences. Lack of use of indicators is not, for example, one of the listed contraventions listed by the police for either offence. Although that list isn’t exhaustive of course!
I do agree, keeping the mini-roundabout information is important, but I don’t think that prevents us from mapping as way in the UK - unless there’s something I’ve missed?
They can be rendered as ways, should the renderer so choose, look at how organic maps renders them and provides routing ins
But as this mainly affects the UK, you really should discuss it with the UK community.
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Interestingly, only ~27% of highway=mini-roundabout tags are located in the UK. However, you’re right, this probably does represent a plurality of usage by country.
(15 216 instances in the UK vs 56 395 globally)
Done some checking in NL. There are a grand total of 79 highway=mini_roundabout nodes. I didn’t check them all, just random quick peeks e.g.:
-
A true (signed) roundabout, raised and kerbed middle island (think truck apron without the undrivable centre island) just small so the mapper didn’t bother to map it with a circle, then cut it up and adapt the routes. Understandably: The junction node is also a Numbered Node in both a Walking Node Network and a Cycle Node Network, and a bus route passes the junction, so that’s some tricky work, especially the bicycle routes and the bus routes.
-
A dot-junction without the roundabout sign, just a dot and a hint of a circle, and priority for whoever is first on the junction. The movement on the junction can’t be called oneway or circular, because even one car will occupy the junction including the middle dot!
-
A junction with a centre island with a pole in the middle, and roundabout signs at some of the entries, but without any give_way signs.
Case 1 I think meets the functional criteria for a mini-roundabout
Case 2 Calling this a mini-roundabout is totally useless. But it doesn’t harm either. However if a renderer decides to display mini-roundabouts as a circular way, I think this one would not match reality.
Case 3 Is not a junction=roundabout nor a highway=mini_roundabout, despite the sign, because there is no priority for traffic on the circle.
So, should we decide to act, I guess still a few mini-roundabouts will remain. Which is more than I would have imagined a week ago!
PS
A prime example of case 2
I think this one has been deliberately designed to mimick a roundabout, but it’s just a regular crossing of two single carriageway roads. If a car goes straight on, it will not move an inch to avoid the centre dot. If two cars are approaching head-on, both wanting to turn left (remember, it’s right hand side traffic) they surely will not (and need not) go around each other. I will remove the highway=miniroundabout tag from this one.
That not disagreeing with me. It’s simply a statement of the obvious. Guilt will be established by admitting the charge, or by a court. I do have some experience with Highways Legislation, and I know drivers are charged because of not indicating but usually where it involves a collision.
It seems more like “could” for both offences. Lack of use of indicators is not, for example, one of the listed contraventions listed by the police for either offence. Although that list isn’t exhaustive of course!
“could” applies to all offences. Your link includes some of the offences that have been charged under Dangerous Driving & Careless/inconsiderate driving charges. As I said before, the starting point is the guidance found in the Highway Code, which advises you to indicate and when to indicate.