<div dir="ltr"><div><div><div><div>It's not so much about the instruction - but about the time penalties.<br></div>Try out some super sharp turns - with different road-speed. there will be like 2-3 minutes penalties... No turn should be sharper than 50-60° angle left if possible - else the routing really breaks down...<br><br></div>Best would be actually to create small artificial roads to make the turn less sharp... (actually 4-5 points are enough - and have most of that turn in the additional mid 2-3 points).<br><br></div>I think adjust turn headings helps there a bit (for bicycle/foot routing - cause actual streets usually don't have relly sharp turns as cars could not do it - but for trails/pathes really awful turns exist (awful for the Garmin algo)...)<br><br><br></div>In case of crossings with 5-6 ways - even a small artifical turnaround would be great....<br></div><div class="gmail_extra"><br><div class="gmail_quote">On 7 August 2015 at 16:40, Gerd Petermann <span dir="ltr"><<a href="mailto:gpetermann_muenchen@hotmail.com" target="_blank">gpetermann_muenchen@hotmail.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
<div><div dir="ltr">
<div dir="ltr">Hi Marko,<br><br><div><span class="">> >// also helps to produce a turn instruction when the main<br>> >// road bends sharply but the side road keeps close to the<br>> >// original heading<br>> <br>> Oh, that would seem to be applicable for a scenario where you have a <br>> grid of highway=residential, and among them a main road (say, <br>> highway=tertiary) that is going like zig-zag within the grid. Could it <br>> be that Garmin is not issuing a turn instruction in this case, when the <br>> main road consists of a single object (with a sharp turn in it)?<br><br></span>Do you have an example OSM id?<span class=""><br><br>> <br>> AFAIR, there was another option for implementing support for <br>> through_route relations, in a case where a main road goes zig-zag <br>> through a village. Is it still present in the code base? Maybe it makes <br>> this case of --adjust-turn-headings redundant?<br><br></span>The evaluation of through-route relations is still in the code, I guess it still<br>works, but IIRC the tag is only rarely used.<br><br><br>I did a few more tests now (without --housenumbers for now).<br>I think the code for --adjust-turn-heading is somehow wrong, e.g.<br>if the calculated route is <br>entering the junction at node 1828873253<br><a href="http://www.openstreetmap.org/node/1828873253" target="_blank">http://www.openstreetmap.org/node/1828873253</a><br>from south going right will not not show a "turn right" instruction<br>when --adjust-turn-heading is used, but it does without the option.<br>Consequently, if the route goes straight on to way 171930600,<br>the instruction is "turn left onto Börtelsdamm" with and <br> no instruction without the option.<br><br>It seems that Garmin uses the "Continue on" instruction only on ramps.<br><br>Reg. ramps I found no positive effect with --adjust-turn-heading, I see the <br>same instructions but sometimes the calculated time is increased, probably <br>because the code increases the angle too much.<br>Maybe the option (and the code) is really obsolete since r3116 which introduced <br>the new routines for writing NOD data:<br><a href="http://www.mkgmap.org.uk/news/2014/03/19/announcement-version-r3116-is-a-major-u" target="_blank">http://www.mkgmap.org.uk/news/2014/03/19/announcement-version-r3116-is-a-major-u</a><br><br>Up to now I did my tests with real data, I'll try to create some test data to find out<br>if there is still a case where --adjust-turn-heading produces better instructions.<span class="HOEnZb"><font color="#888888"><br><br>Gerd<br><br></font></span></div></div>
</div></div>
<br>_______________________________________________<br>
mkgmap-dev mailing list<br>
<a href="mailto:mkgmap-dev@lists.mkgmap.org.uk">mkgmap-dev@lists.mkgmap.org.uk</a><br>
<a href="http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev" rel="noreferrer" target="_blank">http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev</a><br></blockquote></div><br><br clear="all"><br>-- <br><div class="gmail_signature"><div dir="ltr"><div><div><div>Felix Hartman - Openmtbmap.org & VeloMap.org<br></div>Floragasse 9/11<br></div>1040 Wien<br></div>Austria - Österreich</div></div>
</div>