[OSM-talk-be] some thoughts and remarks about border mapping

[Luc Van den Troost]

More and more borders are starting to get mapped. It might be usefull to
use all (or most) the same guidelines and rules to tag them...

info about boundaries is on

http://wiki.openstreetmap.org/index.php/Key:boundary

some thoughts.

Border FROM or BETWEEN

The border of Antwerpen is not just the border of Antwerpen. It always
is the border BETWEEN Antwerpen and something else. 
So a border gets left = Antwerpen; right = Borsbeek

ONE AND MORE

One border often are more borders... The Schelde at the harbout is the
municipality border between Antwerpen and Beveren

At the same time this also is the border between the arrondissement
Antwerpen and Dendermonde, it is the border between the province of
Antwerpen and the province of Oost Vlaanderen. 

If one includes districts or deelgemeenten it also is the border between
Berendrecht-Zandvliet-Lillo (bezali) and Doel. 

How should it be tagged? I would think it is best to tag it with it's
lowest admin_level (8 gemeente, or even 9 deelgemeente)
parts of those borders then could be grouped in a relation for the
higher levels (if I am right, know NOTHING about relations exept that
they exist for such things)

Or is it better to tag it at its highest level (like province in this
case, admin_level 6)

How about the dutch border? It is already there, how does it get linked
so that one (or computers) know to recognise it as a municipality /
district / province / ... border too??


BUILD UP AREAS

On some places, like around Leuven, it looks like borders are used to
mark build up areas (bebouwde kom). 

http://www.informationfreeway.org/?lat=50.88048655029894&lon=4.723059746415672&zoom=13&layers=B0000F000F

Should we mark 'bebouwde kom' with an administrative border? If it is
because of a speed limit there are other tags for it (max_speed) and if
we do, what about zone 30, zone 70, blue parking zone, etc...

COMUNITIES

on the wiki-page mentioned above the 'belgium' specification mention an
administrative level 5 'comunities' (gemeenschappen). 
Comunities are about culture and people. Don't think one can map the
communities in Belgium. It is an admnistrative level, but it's something
that cannot be mapped in a geographical boundary. In the list for
admin_levels for boundaries it shouldn't be present. 


Luc (speedy)