[Tagging] junction=approach

Joseph Eisenberg joseph.eisenberg at gmail.com
Sat Oct 19 10:06:25 UTC 2019

> 1.	How do I obtain a "ruling" on this, or at least a consensus? Is this the correct forum?

There are no official rulings in OpenStreetMap. Consensus develops
when mappers use and document tags in a consistent way.

This is probably the best forum for this question overall, though you
could also ask the UK community.

> 2.     Is “junction=approach” a useful tag?

As the other mapper @c2r mentioned, it might be somewhat useful to
identify ways that approach a junction without preprocessing.

However, in theory database users can get this information by checking
if the way connects to a roundabout, so it's not necessary to add this
tag in most cases.

> 3.	If not, should it be deleted?

I don't see any need to delete these tags. They are not incorrect. It
would be good to document what it means.

> 4.	Could this be done automatically, or should it be by hand?

You should not mass-edit features unless you adhere to the automated
edits code of conduct. This is relevant whether you do it one junction
at a time or in an automated fashion. See

> 5.	Should I amend the Wiki entry for “Key:junction” to deprecate, or warn against this usage?

It might be better to document junction=approach at it's own wiki
page. The page can mention that adding this tag is not usually

Since it's fairly rare, it doesn't have to be mentioned specifically
on Key:junction.

- Joseph

On 10/12/19, Peter Neale via Tagging <tagging at openstreetmap.org> wrote:
> Looking around my local area and trying to fix issues flagged by the iD
> editor, I came across a number of road sections on the approach to
> roundabouts, tagged as “junction=approach”.  I can find no documentation in
> the Wiki to support this usage and it seems illogical to me, as “junction=*”
> should specify the type of junction.  The iD editor also objects, stating
> that “junction-=approach” should be a closed way (i.e. an area object).
> An instance of this is https://www.openstreetmap.org/way/205996585.  This
> was created
> in https://www.openstreetmap.org/changeset/15069009#map=14/52.0589/-0.7514,
> so I consulted the original mapper via Changeset comments, saying,
> “....if I have consulted the history and changeset correctly, [this
> changeset] includes a number of instances (e.g.
> https://www.openstreetmap.org/way/205996585) where you have tagged a road
> flare approaching a roundabout with "junction=approach". I can find no
> documentation in the wiki for this tagging and iD raises it as an issue,
> saying that "Junction=approach" should be a closed way (i.e.a 2-D object, or
> area). Could you explain why you tagged it this way? What did you mean by
> the tag? Is it still relevant?”
> Mapper @c2r has responded, ---------------------------“I've always tagged
> roundabout approaches as junction=approach - I must have picked it up from
> somewhere. Looking at taginfo, there's about 1760 ways tagged as such all
> over Europe:
> https://taginfo.openstreetmap.org/tags/junction=approach#map although I
> appreciate that it doesn't appear to be documented - although very little
> was at the beginning when stuff just sort of evolved.
> “The approaches themselves are pretty standard approaches to roundabouts in
> England, i.e. there is typically a raised centre triangular island, for a
> few meters in length where the carriageway flares and separates from the
> centre. It is not an area. I'd always assumed junction=approach was used as
> a shorthand to prevent navigation software deciding that a U turn at the
> gore was acceptable, without needing to actually specify it as such.
> “I'm not really bothered one way or another as to whether it remains as
> being a tag or not; whether it is relevant depends on whether it is useful
> to renderers or to navigation software. However, with the advent of mass
> aerial imagery and critical mass, I'm not as involved in OSM mapping as I
> was years ago when GPS traces were needed, although still add the occasional
> POI/correction so am active in that regard.
> “I'd suggest asking for a ruling from the powers that be. It'd presumably be
> easy to strip the lot from the database programatically if they weren't
> required/of use.”-----------------
> Advice please.
> 1. How do I obtain a "ruling" on this, or at least a consensus? Is this the
> correct forum?2.     Is “junction=approach” a useful tag?3. If not, should
> it be deleted?4. Could this be done automatically, or should it be by
> hand?5. Should I amend the Wiki entry for “Key:junction” to deprecate, or
> warn against this usage?
> Regards,
> Peter

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