[mkgmap-dev] Strange long distance routes on Nüvi

Mon Jul 31 08:04:09 BST 2017

Hi Andrzej,

I looked at your patch and it seems reasonable to me but 
as a cyclist I'd prefer to use a different tag instead of mkgmap:good_road,
maybe mkgmap:fast_road?
Do you know how this patch influences bicycle routing? 

The special handling of highway=mini_roundabout is somewhat problematic
because that tag should not be used on ways. I also would not use the type
0x0c
for them, so I suggest to remove that rule so that our "mop up" rule catches
them:

# Mop up any unrecognised highway types
highway=* & area!=yes [0x07 road_class=0 road_speed=0 resolution 23] 

Gerd

popej wrote
> Hi Bodo,
> 
> I think Garmin is using some kind of hierarchical routing algorithm. It 
> looks like GPS uses only class 4 and 3 roads for long distances (at 
> least in case of recent nuvis, hiking GPS can be more flexible). For 
> proper routing GPS needs a continuous and reasonably dense notwork of 
> high class roads.
> 
> My patch address 2 problems in default style.
> 
> First are links and roundabouts, which often get lower road class than 
> connected roads. This breaks continuity of high class network and breaks 
> routing. My patch simply increases road class for many links and 
> roundabout types.
> 
> Second problem is low density of good highways in some regions. To make 
> it better, my patch increases road class for international roads. These 
> roads are detected by "ref" and "int_ref" tags, both in objects and 
> relations.
> 
> I have added some small general corrections for 
> "highway=mini_roundabout", "access=hov" and "oneway=reversible".
> 
> There is no direct change for "inc\roadspeed". Maybe patch overrides 
> some of your changes in "lines" file? Anyway, I don't think road speed 
> breaks routing, you can tune it to your liking.
> 
> -- 
> Best regards,
> Andrzej
> _______________________________________________
> mkgmap-dev mailing list

> mkgmap-dev at .org

> http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev

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