<html><body><div style="color:#000; background-color:#fff; font-family:HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif;font-size:10pt">>> An automatic rendering rule will not take care of these particular<br clear="none">>> contexts. Distance could be one rule, or absence of roads.<br clear="none"><br clear="none">> I don't follow the "will not take care of". We are basically talking<br>> about automating the judgement of the cartographer.<br><br><div><span>I mean a general rule where all paths start to be seen at the same zoom level. We need more context specific rules where the only access to residential areas is from paths.<br></span></div><div> </div><div><span style="font-style:italic;color:rgb(0, 0, 191);font-weight:bold;">Pierre <br></span><br></div> <div style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 10pt;"> <div
style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, sans-serif; font-size: 12pt;"> <div dir="ltr"> <hr size="1"> <font face="Arial" size="2"> <b><span style="font-weight:bold;">De :</span></b> Greg Troxel <gdt@ir.bbn.com><br> <b><span style="font-weight: bold;">À :</span></b> Pierre Béland <pierzenh@yahoo.fr> <br><b><span style="font-weight: bold;">Cc :</span></b> Martin Koppenhoefer <dieterdreist@gmail.com>; "dev@openstreetmap.org" <dev@openstreetmap.org> <br> <b><span style="font-weight: bold;">Envoyé le :</span></b> Mardi 7 janvier 2014 20h37<br> <b><span style="font-weight: bold;">Objet :</span></b> Re: [OSM-dev] Renderer issue: highway=service and service=driveway?<br> </font> </div> <div class="y_msg_container"><br><br clear="none">Pierre Béland <<a shape="rect" ymailto="mailto:pierzenh@yahoo.fr" href="mailto:pierzenh@yahoo.fr">pierzenh@yahoo.fr</a>> writes:<br
clear="none"><br clear="none">> In this particular case, if there was a hierarchy of roads, it would<br clear="none">> be less a problem if the rule that I proposed was followed. See<br clear="none">> <a shape="rect" href="https://wiki.openstreetmap.org/wiki/Highway_Tag_Africa" target="_blank">https://wiki.openstreetmap.org/wiki/Highway_Tag_Africa</a><br clear="none"><br clear="none">I think the notion of having primary/secondary be about importance makes<br clear="none">sense. It may be better to try to tag with a characteristic distance to<br clear="none">avoid quantization and arguing.<br clear="none"><br clear="none">First, set motorway aside. We know what the motorway rules are, and all<br clear="none">motorways are important (to first order). Then, in a non-motorway<br clear="none">world, you can ask "what is the shortest typical distance for which many<br clear="none">routes will use this road". Essentially, I'd
argue that (if one decides<br clear="none">to not use motorways), primary highways are likely to be the roads<br clear="none">chosen for distances of 200km or more. Secondary for perhaps 50 km,<br clear="none">and many of the roads that feel like they should be tertiary are used to<br clear="none">get to the next town, or next next town, but not 10 towns (except as<br clear="none">local feeders, not a through route). So that's more like 20 km.<br clear="none"><br clear="none">However, this breaks down in the city (calling only those roads<br clear="none">tertiary); consensus is to have far more tertiaries. My sense is that a<br clear="none">road is properly tertiary if it takes you from one place of 5000 people<br clear="none">to another place of 5000 people.<br clear="none"><br clear="none">However, this population-based argument is a) not really important in<br clear="none">the areas we are talking about and b) not related to
showing roads at<br clear="none">low zoom.<br clear="none"><br clear="none">So maybe roads should be tagged with a typical_distance tag, inferred<br clear="none">From class, and that can be used to render.<br clear="none"><br clear="none">I realize this needs a lot more thought.<div class="yqt6942746041" id="yqtfd32034"><br clear="none"><br clear="none"><br clear="none">> An automatic rendering rule will not take care of these particular<br clear="none">> contexts. Distance could be one rule, or absence of roads.</div><br clear="none"><br clear="none">I don't follow the "will not take care of". We are basically talking<br clear="none">about automating the judgement of the cartographer.<br><br></div> </div> </div> </div></body></html>