<div>Keepright fusses if highways with different layers meet at junctions (because it messes up rendering if the highways are drawn differently). So where you've got a bridge very close to a junction you have to put in a short way for the bridge and a very short way linking the bridge to the junction. Messy, and doesn't always solve the rendering problem, anyway.</div>
<div> </div>
<div>Keepright doesn't fuss if waterways meet with different layers.</div>
<div> </div>
<div>So the simplest is to consider highways to be layer=0 (and put that explicitly on the bridge, cos some people take bridge=yes to imply layer=1), and to make the waterway layer=-1.</div>
<div> </div>
<div>Richard<br><br></div>
<div class="gmail_quote">On Tue, Dec 15, 2009 at 9:07 AM, Mike Harris <span dir="ltr"><<a href="mailto:mikh43@googlemail.com">mikh43@googlemail.com</a>></span> wrote:<br>
<blockquote style="BORDER-LEFT: #ccc 1px solid; MARGIN: 0px 0px 0px 0.8ex; PADDING-LEFT: 1ex" class="gmail_quote">
<div class="im"><br><br>Mike Harris<br><br><br>> -----Original Message-----<br>> From: Steve Bennett [mailto:<a href="mailto:stevagewp@gmail.com">stevagewp@gmail.com</a>]<br></div>
<div class="im">> Sent: 15 December 2009 02:43<br>> To: Anthony<br>> Cc: openstreetmap<br>> Subject: Re: [OSM-talk] Ditches<br>><br></div>
<div class="im">> On Tue, Dec 15, 2009 at 1:31 PM, Anthony <<a href="mailto:osm@inbox.org">osm@inbox.org</a>> wrote:<br>> > In a park is a ditch. There is a very small bridge going<br>> over the ditch.<br>
> > I've tagged the ditch with barrier=ditch. Should the ditch<br>> be layer=-1?<br>> > Even though the park is layer=0?<br>><br>> Layers are only there to explain the relative heights of<br>> things when they meet. No harm will result from marking the<br>
> ditch as layer -1.<br><br></div>See my separate reply - I disagree - what happens when the "level=-1" ditch<br>runs downstream into a "level=0" stream / river - without a waterfall?<br>
<div class="im"><br>> Whether or not it needs to be a lower number than that of the<br>> bridge is an unresolved question.<br><br></div>I disagree - surely the bridge is above the water in the ditch and so - by<br>
your own defintion ('relative heights') it must have a higher level value?<br>
<div class="im"><br>> > Should I use barrier=entrance on the node where the ways overlap,<br>> > bridge=yes on the bridge (which means splitting the way for a very<br>> > short bridge), both, something else?<br>
><br>> There shouldn't be a junction between the bridge and the<br>> ditch, so no need to mark anything barrier=entrance. Just<br>> mark the whole bridge bridge=yes.<br><br></div>Agree - but the way has to be split for the bridge=yes section.<br>
<div class="im"><br><br>> > <a href="http://wiki.openstreetmap.org/wiki/Image:IMG_6784.JPG" target="_blank">http://wiki.openstreetmap.org/wiki/Image:IMG_6784.JPG</a><br>> > <a href="http://wiki.openstreetmap.org/wiki/Image:IMG_6783.JPG" target="_blank">http://wiki.openstreetmap.org/wiki/Image:IMG_6783.JPG</a><br>
><br>> The path:<br>> highway=footway<br>> (possibly bicycle=yes)<br>><br>> It then meets a bridge:<br>> highway=footway<br>> bridge=yes<br>> layer=1<br>><br>> Then another path:<br>> highway=footway<br>
><br>> Meanwhile, unconnected, but crossing the bridge:<br>> waterway=drain<br>><br>> Not sure I'd even mark it "barrier=ditch" after all that. I'd<br>> also only specify a layer for the bridge, not the ditch/drain.<br>
<br></div>Agree - enough to mark it as a stream or, if that is felt to be too 'big'<br>then waterway=ditch.<br><br>Also agree that the bridge, rather than the ditch, should carry the layer<br>tag (see my comment above). Doesn't this rather imply that the ditch has the<br>
same layer value as the level=0 surroundings (as I suggest) rather than<br>level=-1 (as per your 'no harm' suggestion) - and that the bridge has a<br>layer value higher than 0, so presumably level=1 (as I suggest)?<br>
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<div class="h5"><br>> Steve<br>><br>><br>><br><br><br>_______________________________________________<br>talk mailing list<br><a href="mailto:talk@openstreetmap.org">talk@openstreetmap.org</a><br><a href="http://lists.openstreetmap.org/listinfo/talk" target="_blank">http://lists.openstreetmap.org/listinfo/talk</a><br>
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