[Tagging] Traffic_sign discussion

Tobias Knerr osm at tobias-knerr.de
Tue Oct 9 18:36:34 UTC 2018

On 09.10.2018 17:42, yo paseopor wrote:
> So Please , let's talk about it. What will be the correct way to tag a
> traffic sign?

How about the existing tagging scheme for traffic signs on nodes,
documented at https://wiki.osm.org/Key:traffic_sign ?

To sum it up:

- Place a node for the traffic sign into the highway=* way.¹
- Tag the node as traffic_sign=<ISO>:<ids>.
- As with your suggestion, <ISO> is the ISO country code.
- <ids> is composed of one or more country-specific traffic sign ids, as
an ordered list separated by commas.
- If there are multiple groups of traffic signs, these groups are
separated by semicolons.
- Custom inscriptions on a sign are appended to the sign id in square
brackets [].

¹ The page also documents how to map traffic signs next to the way, but
I understand you would like to talk about mapping them as part of the way.

I haven't seen a convincing reason for changing this yet. I'm aware of
the general argument against semicolon-separated or comma-separated
lists of values, but imo this is less critical for keys that have
well-defined semantics for such characters.

> traffic_sign:direction=forward/backward/both
> Also accepts other facing directions like 90/270...

In my opinion, traffic signs should use the normal direction=* key for
angles such as 90 or 270. This usage is part of the approved proposal of
that key:


Using traffic_sign:direction specifically for the "forward" and
"backward" values, as discussed in the recent iD-related thread, is fine.

> https://wiki.openstreetmap.org/wiki/Proposed_features/Extended_traffic_signs_tagging

I find it hard to discuss this proposal because it includes so many
different ideas:

- introducing a system of "categories" for signs: caution, warning, etc.
- using :2, :3 etc. instead of comma-separated ids
- using human-readable values instead of unambiguous national IDs
- re-purposing maxspeed (and maxspeed:hgv etc.) for traffic sign mapping
- adding a side=* key
- improving destination sign and roundabout mapping

Trying to change all that at once likely leads to discussions that mix
all sorts of loosely related topics. And there's not really a reason why
e.g. introducing the side=* key would also require using numeric
suffixes. These are independent changes that could easily be discussed

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