|
I am working on an area near my home town, adding streams and bridges where indicated. However, there are many cases in which a small stream passes beneath a gravel road in a culvert. That is, no actual bridge is involved. What is the best way to create and tag such crossings? |
|
I believe the official received wisdom is to just tag a segment of the stream as tunnel=culvert (and, as with bridges, don't put a shared node at the crossing). At the moment this does not render in Mapnik as any different from any other stream segment, but then, it doesn't really need to, and any renderers or routers that would actually make use of the culvert information have it. Thanks blahedo, You mean, make that stream segment a way? What sort of way - an Unknown Road maybe? When I do that in the "Advanced" panel it looks like this in the "Simple" panel: Tunnel (culvert). I'm using Potlatch2 and do not yet know for sure how to set tunnel=culvert. I've attempted it for one of my crossings and would like you, or someone else, to to look at it and make it "proper". The latitude coordinates are not showing on Potlatch for some reason - yes, I have that set in my options but Google Earth shows this crossing at (N59.708393, W151.345675). Thanks for your help.
(04 Dec '12, 04:36)
AlaskaDave
3
A "way", in OSM parlance, is just a sequence of connected nodes---which could represent a stream, a road, a building outline, or anything else. It looks like you figured out how to identify a segment of a way, and how to tag it as tunnel=culvert; you don't want to mark a stream as a highway, though! Just leave it as a stream (I've switched it back for you). As an aside, for crossings where the lower item is in a tunnel, you don't need the upper item to also be going over a bridge. Generally it's either/or.
(04 Dec '12, 05:20)
blahedo
|
|
One method of learning tagging is to look around the map for another one, the search box may help in some cases. Then open the editor to look at it for an example of what to do. Bear in mind it may not be a good example though. someone may give you a permalink to one if you lucky. |
Once you've edited it, perhaps you could post a permalink to the area (either here or on IRC) so that people can say "yes! that's what we meant" or "no - not quite..."?
@blahedo - sorry I missed your 2nd reply until just now. Thanks. I figured it out after I realized what the nomenclature tunnel=culvert actually means and that it is set in the advanced tab of the Potlatch2 editor. I have several more to change but it will be easy now.
@Andy - thank you as well. I used that method for several other projects. I did find a tally of the various methods used to represent streams running through culverts somewhere and the most popular by far is to split a small stream segment off the main one and tag it tunnel=culvert and level = -1.