Hi,
on Sunday, 10 February 2008 08:34:31 -0800, Karl Newman <[EMAIL PROTECTED]> writes: > On Feb 10, 2008 4:21 AM, Frederik Ramm <[EMAIL PROTECTED]> wrote: > > > Since trees lining a way/street are such a common occurence, why > > > not have a simple additional tag to the main road. > > > > > > lined_by_trees=yes/no/left/right > > > > I'm a bit unhappy about needlessly inflating the importance of the > > direction of ways. Long-term, I would actually like to get rid of the > > direction and express everything in relations. This means, that you find it necessary to have something like a "direction" or a "side", both of this features related to a way? But you don't want to express a direction or a side by the _implicit order_ of the way nodes. > > The reasons for this > > are > > > > (a) the direction is too easily changed, sometimes by mistake ... because none of the current OSM editors show direction- or side-related tags explicitly. > > (b) there might be multiple conflicting things that rely on the > > direction, e.g. a road that is oneway from A to B but has a > > slope from B to A > > > > Anything with "left/right" in it also relies on direction. I'd prefer > > "east/west/north/south", or using an explicit relation that says > > "trees on the right between nodes A and B along road C". I am against east/west/north/south because there are a lot of ways/areas/things which do not go straight ahead. > Okay, this thread is at risk of spinning wildly off-topic, but I've been > thinking about this situation recently. It seems to clamor for the use of > specialized relations that are "direction-aware". That way, if a way is a > member of a relation and has directional properties (left/right), then the > editors could look for those relations when the way is reversed and either > fix them automatically or at the minimum raise a warning dialog. > > I also had some other ideas about enforcing referential integrity for > another type of specialized relation (if one or more node relation members > is required to be part of a way relation member, then enforce that rule). > That rule could actually be enforced by the API. > > These specialized relations would just give some structure to the wide-open > relation type, without implying anything about the nature of the relation. > It could possibly be accomplished through special tags on the existing > relation structure. Do you have any propositions how this will look like or how this should be done? A few days ago I have started a new proposal for a "Segmented Tag", which relates a set of tags to a directed or undirected part of a way (I have called this part "segment" inspired by GDF's "Segmented Attributes"). I have not found the time yet to finalize the proposal adding some examples, nonetheless it can already be found in the OSM Wiki (Relations/Proposed/Segmented Tags). Best wishes, -bernd _______________________________________________ talk mailing list talk@openstreetmap.org http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk