[OSM-talk] Rendering of tracktype

[Cartinus]

On Friday 13 June 2008 03:54:42 Frederik Ramm wrote:
> Hi,
>
> > If there is some legal reason for it to be only accessible by bikes and
> > tractors, then you'll need to use access restrictions
> > (access=no;agriculture=yes;bicycle=yes;foot=yes) anyway, as there is
> > nothing that says normal cars are not allowed to use tracks of grade1
>
> I don't know if this is a German specialty but the tracks being
> discussed mainly carry the following sign disallowing all motorized
> traffic:
>
> http://de.wikipedia.org/wiki/Bild:Zeichen_260.svg
>
> And then the following exemption explicitly allowing
> agricultural/forestry use:
>
> http://de.wikipedia.org/wiki/Bild:Zusatzzeichen_1026-38.svg
>
> Surely it is possible to tag these ways as
> access=no,agriculture=yes,forestry=yes,bicycle=yes,horse=yes,foot=yes
> etc.etc. but it seems wrong to me; the signage *forbids* certain
> accesses and allows all others. You are suggesting to turn around the
> logic with your tagging: Forbid all accesss and then explicitly allow
> some. Which obviously breaks if new access types are introduced later.

I'm doing exactly what you want to do. Except I was thinking about the 
following sign: http://de.wikipedia.org/wiki/Bild:Zeichen_250.svg
The closest tag I know for this is access=no, unless you want to invent the 
new tag vehicles=no

> What's more, in terms of kilometres we have vastly more of these in
> Germany than, say, pedestrian zones in cities. Nobody says that we
> should do away with highway=pedestrian even though you could perfectly
> well tag it as highway=residential,access=no,foot=yes - pedestrian areas
> are something that is known to everyone and so we just tag "here is a
> pedestrian area" instead of trying to describe what exactly a pedestrian
> area is.
>
> So it is only understandable that the community is looking for an easy
> way to tag these kinds of tracks, and until now many seem to have used
> highway=track,tracktype=grade1 for them.

Maybe many have discussed this implicit access restriction on the German 
mailinglist. But I have seen nothing about it in the wiki nor in the talk 
list. So from my (Dutch) viewpoint there are no implicit access restrictions 
on a grade1 track. In contrary the very definition of it implies it is 
physically possible to drive a normal car along it. For a pedestrian highway 
however the implicit access restrictions are clearly defined and worldwide 
the same.

> Maybe we should simply stop trying to find international lingo for
> something that seems to be a national type of road, and just recommend
> that people tag these things as "highway=land-und-forstwirtschaft", with
> implied access restrictions.

That is probably a better idea than to expect any routing program to know that 
when a track of grade1 is in Germany it has different access restrictions 
then in e.g. the Netherlands.

-- 
m.v.g.,
Cartinus