<div dir="ltr">Thank you all for the explanations.<div>
<span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">I think that my issue might have to do with UK English usage. I would never call a road tunnel a "culvert", I <span> </span></span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;text-decoration-style:initial;text-decoration-color:initial;background-color:rgb(255,255,255);float:none;display:inline">typically only work and map in a rural setting and</span><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:small;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline"><span> </span>a culvert is only a passage way for water, and is only used at a road or path crossing. </span> </div><div>
<br><div>While a ford is something shared by a road and a stream one is still under the other, but the rules for rendering assume that the road is underneath. In the <a href="https://wiki.openstreetmap.org/wiki/Key:ford">OSM ford wiki</a> one photograph shows the path on top of the ford using the stepping stones. <br><div>The <a href="https://en.wikipedia.org/wiki/Culvert">Wikipedia </a>reference cited on the <a href="https://wiki.openstreetmap.org/wiki/Tag:tunnel=culvert ">OSM culvert wiki</a> only shows stream examples. </div><div>Therefore, why not have a rendering rule for culverts in the same way there is a rendering for a ford?<br></div></div></div><div><br></div><div>This has been an interesting thought process and I'm probably just lazy not wanting to split a watercourse twice and add a tag to the way as opposed to snapping a road or watercourse node and adding a tag to the node.</div><div><br></div><div>Keep mapping</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Wed, Feb 28, 2018 at 5:11 PM, Dave Swarthout <span dir="ltr"><<a href="mailto:daveswarthout@gmail.com" target="_blank">daveswarthout@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div dir="ltr">
<span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:16px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">>If 2 ways share a node, then they must be connected to each other. ie on the same layer. So one can't be above/below the other. A road and a stream crossing on the same layer is a ford.</span><br style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:16px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:16px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">>If you tag the shared node as a tunnel, then you don't know which way goes through the tunnel. Does the stream go through a tunnel, or does the road go through a tunnel, or both?</span><br style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:16px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><br style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:16px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial"><span style="color:rgb(34,34,34);font-family:arial,sans-serif;font-size:16px;font-style:normal;font-variant-ligatures:normal;font-variant-caps:normal;font-weight:400;letter-spacing:normal;text-align:start;text-indent:0px;text-transform:none;white-space:normal;word-spacing:0px;background-color:rgb(255,255,255);text-decoration-style:initial;text-decoration-color:initial;float:none;display:inline">>It is much more useful to map tunnels/bridges as a way. If you know there is a tunnel, but don't know how long the tunnel is, you can estimate it. ie based on the width of the road. You can add a note to say the exact >length/position is estimated</span> <br><div><br></div><div>Excellent explanation. Agree totally.</div></div><div class="gmail_extra"><br><div class="gmail_quote">On Thu, Mar 1, 2018 at 7:48 AM, Craig Wallace <span dir="ltr"><<a href="mailto:craigw84+osm@gmail.com" target="_blank">craigw84+osm@gmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><span>On 2018-02-28 23:21, Vao Matua wrote:<br>
<blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
François<br>
<br>
I don't have an example. I was trying to think of an example where layer would be needed for a stream/road crossing. A pipe would probably be a better example.<br>
<br>
Sorry to cause a distraction.<br>
<br>
My real question is "Why not allow tunnel=culvert to be a node?"<br>
<br>
Emmor<br>
</blockquote>
<br></span>
If 2 ways share a node, then they must be connected to each other. ie on the same layer. So one can't be above/below the other. A road and a stream crossing on the same layer is a ford.<br>
If you tag the shared node as a tunnel, then you don't know which way goes through the tunnel. Does the stream go through a tunnel, or does the road go through a tunnel, or both?<br>
<br>
It is much more useful to map tunnels/bridges as a way. If you know there is a tunnel, but don't know how long the tunnel is, you can estimate it. ie based on the width of the road. You can add a note to say the exact length/position is estimated.<div class="m_3128364245549952257HOEnZb"><div class="m_3128364245549952257h5"><br>
<br>
______________________________<wbr>_________________<br>
Tagging mailing list<br>
<a href="mailto:Tagging@openstreetmap.org" target="_blank">Tagging@openstreetmap.org</a><br>
<a href="https://lists.openstreetmap.org/listinfo/tagging" rel="noreferrer" target="_blank">https://lists.openstreetmap.or<wbr>g/listinfo/tagging</a><span class="HOEnZb"><font color="#888888"><br>
</font></span></div></div></blockquote></div><span class="HOEnZb"><font color="#888888"><br><br clear="all"><div><br></div>-- <br><div class="m_3128364245549952257gmail_signature" data-smartmail="gmail_signature"><div dir="ltr">Dave Swarthout<br>Homer, Alaska<br>Chiang Mai, Thailand<br>Travel Blog at <a href="http://dswarthout.blogspot.com" target="_blank">http://dswarthout.blogspot.com</a></div></div>
</font></span></div>
<br>______________________________<wbr>_________________<br>
Tagging mailing list<br>
<a href="mailto:Tagging@openstreetmap.org">Tagging@openstreetmap.org</a><br>
<a href="https://lists.openstreetmap.org/listinfo/tagging" rel="noreferrer" target="_blank">https://lists.openstreetmap.<wbr>org/listinfo/tagging</a><br>
<br></blockquote></div><br></div>