At 2010-05-24 17:55, Nathan Edgars II wrote: > > Secondly, it is apparent that you didn't check the layer tags of all > features (such as bridges) that pass over these "ground-level features". > Now there are many instances of layer-0 bridges crossing over roads that > do not have any layer tags. > >Sounds like the problem is tagging the bridges as layer=0. A bridge >is, by definition, usually above the immediate ground level.
It's above the ground below it, but not necessarily that on either side of it. When there is no change in actual elevation between the bridge and the road segments connecting to it, why should they have different layer values? > If you >wish, I can go looking for bridges tagged as layer=0 and change them >to layer=1. I totally disagree. When surveying, I look at the reality of the elevation of the bridge compared to all the layer-0 features around it. If it is at the same elevation, the bridge stays at layer 0 and whatever it crosses is tagged as layer=-1. This correctly represents the "ground truth". This is very commonly the case with concrete drains/canals. It has the added advantage of not requiring rework when you add a new feature to an area - you simply tag that feature with the correct actual layer and no other features need to be edited. It seems we had this discussion a while ago, where someone wanted to auto-edit all bridges at layer 0 to layer 1. IIRC, consensus was against it, particularly because there was no plan to fix any surrounding features that conflicted with the new layer (like an existing bridge at layer 1 over the layer 0 bridge, which would have to be moved to layer 2). -- Alan Mintz <alan_mintz+...@earthlink.net> _______________________________________________ Talk-us mailing list Talk-us@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-us
