[mkgmap-dev] crude routing of my gpsmap 276Cx

Fri Sep 27 09:01:18 BST 2019

Hi

It doesn't work like this. The OSM tags can express situations that are
much more complicated than can be represented in the GARMIN IMG format
and mkgmap processing transforms OSM tags into the the simpler GARMIN
data structures. A particular GARMIN device (or other software, eg
Basecamp) will use the IMG data for showing the map and routing, but
it's behaviour might be different from other devices.

Most of the handling of access={yes/no/destination/private/...} and
similar values for motorcar/bicycle/pedestrian/... is done in the
default style by rules in inc/access and the rules here have to make
choices of which tags/values to use and to ignore others that cannot be
represented. 

An access value of destination will normally sets the flag
mkgmap:throughroute=no on the road. This is used by later mkgmap java
code to add something that prevents a route being calculated using this
road as an intermediate part of the route.

There is nothing to represent weight restrictions within IMG. You
probably don't want to remove the destination tag because that would
result in more routes being able to use the road in question.

It depends what the map is for. You could change the weight restriction
into forbidding trucks with something like:

weight>someval {add hgv=no}

(but mkgmap doesn't have weight conversion functions)

Then, with the transport mode set to 'Truck' on the Garmin device, it
wouldn't use this road. 

NB: my newer Garmin device has abandoned the ability to route for
Truck, Bus, Emergency, Taxi or Delivery; it just allows Car/Motorcycle,
Pedestrian and Bicycle.

Regards
Ticker

On Thu, 2019-09-26 at 20:28 +0200, DD8KQ wrote:
> Hi
> 
> this afternoon i'm thinking about to add a rule in my style something
> like this : if access=destination and maxweight=xxx remove the tag
> access=destination ? Do you think its a good way to fix that problem
> if
> some garmin devices don't look at all tags ( the ones which are
> specially designed for camper, busses and lorries should do that) ?
> 
> For my opinion the used tags for that street are ok as it is not
> allowed
> for cars havier than 7.5t to use that street
> 
> Am 26.09.2019 um 10:31 schrieb Gerd Petermann:
> > Hi Manfred,
> > 
> > Just to make that clear:
> > I think that the long route is correct given the tags of the
> > mentioned ways if the vehicle is a car. So, your first goal should
> > be to correct the tagging.
> > 
> > Gerd
> > 
> > ________________________________________
> > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> > von manfred.haiduk <manfred.haiduk at freenet.de>
> > Gesendet: Donnerstag, 26. September 2019 10:20
> > An: Development list for mkgmap; dd8kq at gmx.de
> > Betreff: Re: [mkgmap-dev] crude routing of my gpsmap 276Cx
> > 
> > Thank you for the information. I will try this later this week and
> > keep you informed. BTW, i can remember some years ago when i have
> > not used OSM Data on may Garmin but on a smartfone navigation
> > system with OSM, there was the same fault on that device with a
> > long detour. But after some data updates the routing failure on
> > that device was gone
> > 
> > 
> > 
> > Von meinem Samsung Gerät gesendet.
> > 
> > 
> > -------- Ursprüngliche Nachricht --------
> > Von: Gerd Petermann <gpetermann_muenchen at hotmail.com>
> > Datum: 26.09.2019 09:52 (GMT+01:00)
> > An: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>, 
> > dd8kq at gmx.de
> > Betreff: Re: [mkgmap-dev] crude routing of my gpsmap 276Cx
> > 
> > Hi Manfred,
> > 
> > I don't know the actual signs and I don't care if the tagging is
> > right or wrong. At least the combination of bicycle=yes and foot=no
> > on https://www.openstreetmap.org/way/25285589 looks very wrong:
> > bicycle=yes
> > fixme=check access rules
> > foot=no
> > highway=tertiary
> > maxspeed=30
> > maxweight=7.5
> > name=Brandenberger Straße
> > ref=K 30
> > 
> > Anyway, it seems that mkgmap sets the correct flags for the road,
> > the Garmin algo seems to simply ignore the "no-through-route" flag
> > when the detour is
> > too long. I've tried this with a sample file where the shortest
> > route goes through a road with access=destination +
> > highway=residential and the longer route
> > just has ways with highway=residential. As long as the detour is
> > rather small Mapsource takes the longer (allowed) route when using
> > the car profile.
> > All other profiles seem to always use the shorter route. So, either
> > something is wrong in the map data (problem in mkgmap) or something
> > is wrong in the Garmin algo.
> > 
> > Please try if you can reproduce the long route using a map created
> > with mkgmap r4292 and the default style coming with that version.
> > 
> > Gerd
> > 
> > ________________________________________
> > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im Auftrag
> > von manfred.haiduk <manfred.haiduk at freenet.de>
> > Gesendet: Donnerstag, 26. September 2019 09:14
> > An: Development list for mkgmap; dd8kq at gmx.de
> > Betreff: Re: [mkgmap-dev] crude routing of my gpsmap 276Cx
> > 
> > 
> > 
> > For your additional information, i think the tag access=destination
> > is to be seen with the additional tag for weight limit, as the
> > street is not allowed to be used for cars heavier than 7.5 tons
> > 
> > Von meinem Samsung Gerät gesendet.
> > 
> > 
> > -------- Ursprüngliche Nachricht --------
> > Von: Gerd Petermann <gpetermann_muenchen at hotmail.com>
> > Datum: 26.09.2019 08:55 (GMT+01:00)
> > An: Development list for mkgmap <mkgmap-dev at lists.mkgmap.org.uk>, 
> > dd8kq at gmx.de
> > Betreff: Re: [mkgmap-dev] crude routing of my gpsmap 276Cx
> > 
> > Hi Manfred,
> > 
> > I tried to reproduce your results with BC but I get a different
> > route.
> > at the moment I wonder why Mapsource shows the shorter route when
> > using car/motorcycle. The ways
> > https://www.openstreetmap.org/way/25285586 and 
> > https://www.openstreetmap.org/way/25285589
> > both have the tag access=destination, so my understanding is that
> > cars should not be routed through them, but this seems to be
> > ignored.  I'll have to find out why.
> > 
> > Gerd
> > 
> > ________________________________________
> > Von: DD8KQ <dd8kq at gmx.de>
> > Gesendet: Mittwoch, 25. September 2019 14:53
> > An: Development list for mkgmap; Gerd Petermann
> > Betreff: Re: [mkgmap-dev] crude routing of my gpsmap 276Cx
> > 
> > Hi Gerd
> > 
> > it's really weird. Trying this with MapSource you are right, there
> > is no
> > long detour. But, then, i tried the same with BaseCamp and you know
> > what, BaseCamp produced on my Laptop this detour, see attached
> > picture
> > Test2.
> > 
> > And just for testing, i tried the same area on a Smartfone running
> > the
> > Navigator App with OSM maps, and this progromm is routing the same
> > detour, see picture screenshot.
> > 
> > So for me there must be something in the OSM Source regarding the
> > street
> > K30 which will cause the strange routing. But my experience is too
> > small
> > to figure it out
> > 
> > Am 25.09.2019 um 11:12 schrieb Gerd Petermann:
> > > Hi Manfred,
> > > 
> > > No idea. I cannot reproduce the result with the default style in
> > > Mapsource. I tried with vehicle car as well as with cycling or
> > > pedestrian, I never get the long detour.
> > > Can you reproduce it with Mapsource? If yes, please provide more
> > > details about the routing settings.
> > > 
> > > ________________________________________
> > > Von: mkgmap-dev <mkgmap-dev-bounces at lists.mkgmap.org.uk> im
> > > Auftrag von DD8KQ <dd8kq at gmx.de>
> > > Gesendet: Dienstag, 24. September 2019 21:58
> > > An: Development list for mkgmap
> > > Betreff: [mkgmap-dev] crude routing of my gpsmap 276Cx
> > > 
> > > Hi
> > > 
> > > may be that somebody has an idea why the routing of my gpsmap
> > > 276Cx is
> > > so crude. I'm using almost the standard style to build my own
> > > garmin
> > > maps. And as the example is mostly in the vicinity of my
> > > hometown,i had
> > > not experienced this error before, as i need not a gps in my home
> > > area.
> > > If you look at picture 20190924_173131.jpg this is a routing i
> > > would
> > > expect to the destination, short and fast. If you look at
> > > 20190924_173229.jpg, the destination is only a few meters away
> > > from the
> > > first one, the routing is nearly three times more than before
> > > with the
> > > same settings on my device. I would appreciate any advice what to
> > > change
> > > or any hint where i can look for why this could happen.
> > > 
> > > Btw, if i change the setting to use bicycle routing, the device
> > > will use
> > > for both destinations the expected way
> > > 
> > > --
> > > 
> > > #####################################################
> > > 
> > >         Viele Grüße und 73 de Manfred Haiduk, DD8KQ
> > >         e-mail mhaiduk at t-online.de dd8kq at gmx.de
> > > 
> > > #####################################################
> > > 
> > > _______________________________________________
> > > mkgmap-dev mailing list
> > > mkgmap-dev at lists.mkgmap.org.uk
> > > http://www.mkgmap.org.uk/mailman/listinfo/mkgmap-dev
> > > 
> > --
> > 
> > #####################################################
> > 
> >        Viele Grüße und 73 de Manfred Haiduk, DD8KQ
> >        e-mail mhaiduk at t-online.de dd8kq at gmx.de
> > 
> > #####################################################
> > 
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> --
> 
> #####################################################
> 
>       Viele Grüße und 73 de Manfred Haiduk, DD8KQ
>       e-mail mhaiduk at t-online.de dd8kq at gmx.de
> 
> #####################################################
> 
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