> Sent: Donnerstag, 6. März 2025 um 20:46 > From: "thigpen--- via Tagging" <tagging@openstreetmap.org> > To: TAGGING@OPENSTREETMAP.ORG > Subject: [Tagging] MAST RELATION > > EACH ELEMENT SHOULD BE TAGGED AS A NODE WHERE THEY ARE IN THE WORLD, EVEN IF > THAT MEANS OVERLAPPING NODES.
From a data organization point this is a bad idea, because a) the same information (lat/lon) is stored multiple times needlessly b) the position of the pole does not change with the attach- ments and most people will understand pole+attachments as a single object and one of osm's conventions is: one object on ground should match (exactly) one object in the database, see https://wiki.openstreetmap.org/wiki/Good_practice For guideposts three defacto standards have evolved, described at https://wiki.openstreetmap.org/wiki/Tag:information%3Dguidepost 1) destination=* 2) Relation:destination_sign (similar to what you intend, put only a single node/osm-object for the pole/mast is used) 3) direction_north=*, direction_east=*, ... direction_northeast=* The tag-based approach is imho sufficient where the attachements of the pole are uniform (homogeneous) - i.e. 1) or 3); .. creating one relation for each attachment if they are heterogeneous - compare 2) - could probably be justified by the need to store tag sets per attachments which might overlap key-wise (key collision; for instance, in the event generic tags like color=* or location=* are to be used to further speficy a street_sign and a traffic_sign mounted on the same pole) Intuitively I'd suggest considering copying the approach described by method 2) above, because each attachement (street_sign, destination_sign, traffic_sign, etc.) ''relates'' to the same physical object it is attached to. (while you can view the attachements as single physical entities as well, this is cumbersome with osm, because location-wise they'd only differ in height and ele=* is a somewhat optional key, while lat/lon are primarily used to identify a node, the most basic bit of information to relate to a physical object on ground within the osm ecosystem). However, if you have to different masts/posts/poles standing close, but separately, next to each other, imho, two nodes (non-overlapping) should be used. There may be objects where 'separateness' is hard to decide, e. g. if they are physically linked above ground in some way, or have a tripod shape, separate on ground but touching at the top.. Overall I'd suggest getting familiar with the approaches already in use for information=guidepost above and extend from those or reuse/recycle these. Greetings _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
