[mkgmap-dev] [PATCH v1] grok unpavedness

Wed Dec 9 10:44:34 GMT 2009

Hi Steve,

On Wed, 09 Dec 2009 10:27:33 +0000
Steve Hosgood <steve at tallyho.bc.nu> wrote:

> Mark Burton wrote:
> > Hello all,
> >
> >   
> >> congratulations to your success with the unpaved bit.
> >>     
> >
> > Thanks Johann.
> >
> >   
> >> For the keyword I would use mkgamp:unpaved, as some others has suggested 
> >> too. In my opinion most if not all tags used by mkgmap should start with 
> >> this prefix and should be translated in the style file.
> >>     
> >
> > I agree. Therefore, I propose that we use:
> >
> > mkgmap:unpaved to tag ways that are "unpaved"
> >
> > mkgmap:ferry to tag ways that are "ferries"
> >
> > Mapping from OSM tags can be done in the style file.
> >
> > Is everyone happy with that? If so, I will make the change and commit
> > it.
> >
> >   
> 
> I disapprove.
> 
> The trouble with the "mkgmap:unpaved=???" approach is that it duplicates 
> existing functionality in OSM. We should strive to get the existing 
> functionality better specified if it doesn't already do the job for us. 
> Otherwise, mapping effort will be spent on adding a set of tags to OSM 
> which only benefit the Garmin routable maps project. What about the 
> TomTom people? Or the AndNav2 users? They'll want to know about 
> routeable or unrouteable unpaved roads too.

The whole point of using a mkgmap: prefix is that it does not force a
particular OSM tag to be used for a garmin gps specific purpose. When an
"approved" OSM tag (is there such a thing?) has a "meaning" that
coincides with a garmin gps capability (e.g. oneway) then it makes
sense for mkgmap's behaviour to be controlled by the OSM blessed tag.
Otherwise, it's better not to pollute the OSM tag namespace or overload
the meaning of existing OSM tags.

> 
> Unrouteable unpaved roads are a real-world fact, not a 'mkgmap' feature.
> 
> 
> I do agree though that OSM's tagging for road surfaces is a bit of a 
> mess, but it needs an OSM-level cleanup if that's a problem, not at 
> mkgmap-level.
> 
> AFAIK there are "surface=???" "smoothness=???" "mtb:scale=???" 
> "sac_scale=???" "rtc_rate=???" tags in OSM, all of which (sometimes in 
> combinations) ought to be enough to give mkgmap the clues needed to set 
> the routeability of a given way. Plus "access=???" and "<vehicle>=no" of 
> course.
> 
> Not just that, but those tags already exist. We should be using them.
> Steve

Isn't that one job of the style file, to transform the OSMish tags into
garmin specific tags?

Cheers,

Mark

PS - I do now wonder if the carpool tag should be changed to
mkgmap:carpool?