[Tagging] new access value

Friedrich Volkmann bsd at volki.at
Fri Oct 9 18:54:25 UTC 2015


On 09.10.2015 13:39, Richard Fairhurst wrote:
> localised meaning does not always have to be parsed into universal
> tags.
> 
> Here in the UK we have very specific access legislation for paths. On a
> bridleway, for example, cycling is permitted, but cycle racing is forbidden,
> and cannot be authorised (whereas it can be authorised on other rights of
> way). Then we have "restricted byways". And "byways open to all traffic".
> And "unclassified county roads". And so on.

Sounds more like a road type issue than an access tags issue. Strange
regulations for certain road types exist in most if not all countries,
including mine. These regulations should be documented at
http://wiki.openstreetmap.org/wiki/OSM_tags_for_routing/Access-Restrictions#United_Kingdom.

> It's madly complex. It would be inappropriate to ask the rest of the world
> to accept special tag values just for this specific use, but on the other
> hand, it's not realistic for UK mappers to break this down into 30 'atomic'
> tags per path. (Especially because the permissions for each path type do
> occasionally get redefined, as per
> http://www.legislation.gov.uk/ukpga/2000/37/contents.)

We should avoid explicit tagging of access restrictions that are defined by
law. By declaring implicit defaults on the aforementioned page, we only need
to change one line on that page instead of myriads of ways whenever a law
changes.

> So we use the standard OSM broad-brush duck tagging (highway=track,
> highway=footway, highway=cycleway etc.) and add a UK-specific value to
> record the legal status of the path (designation=public_bridleway,
> designation=restricted_byway, designation=byway_open_to_all_traffic etc.).
> That way, it's easy to map, easy to parse in outline, possible to parse in
> detail, and doesn't impose a burden on the 95% of non-UK mappers or the 99%
> of data consumers who don't care.

However, the data consumers who do care have a hard time. You deliver them
non-standard tags they either miss completely or don't understand. The
designation=* proposal was voted down long ago. International usage of
designation=* is a mess, see taginfo. There's no way applications can use
this. OSM is an international project, don't use proprietary tags.

-- 
Friedrich K. Volkmann       http://www.volki.at/
Adr.: Davidgasse 76-80/14/10, 1100 Wien, Austria



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