[OSM-talk] Fwd: Nav4All navigation shut down by Navteq

Martin Koppenhoefer dieterdreist at gmail.com
Wed Feb 3 15:21:16 GMT 2010


2010/2/3 Richard Fairhurst <richard at systemed.net>:
> Um, yes, I do know the rules vary between countries.

> Firstly, like I say, you can accept that highway=cycleway implies foot=yes
> and bicycle=yes. Which it does for exactly the same reason that the tags are
> in English, the server code is in Ruby and this mailing list is called
> "talk" rather than "frogs": the chap who got there first decides.


well, the chap that first used cycleway might have been an Englishman,
and might have had in mind that pedestrians are allowed, when tagging
highway=cycleway, but there is absolutely no logic or "natural
meaning" for cycleways to deduct access rights for pedestrians. IMHO
the only thing you can assume is bicycle=yes. As the wiki doesn't
speak about implications on foot (or at least most of the time
didn't), you cannot assume anything for pedestrians on bicycles as
long as you don't
a) check for the position (inside which country) and local legislation/habits
b) have an explicit tag aside (like foot=no/yes)

> And your
> argument that people won't tag "highway=cycleway; foot=no" but will tag
> "highway=path; bicycle=designated; foot=no" is batshit insane.

I wasn't talking about paths, I was pointing out that "walks like a
duck, talks like a duck" is not working automatically, because German
ducks are already too different from English ducks, and I don't want
to know about Chinese ducks.

> Or, you can agree that highway=cycleway will mean something different in
> Germany to the UK. No-one is stopping you from doing this. And, funnily
> enough, it's exactly what we do with most other values for the highway tag:
>   http://wiki.openstreetmap.org/wiki/Key:highway#International_equivalence

yes, I agree, still if you made a routing application with more than
national coverage you either would have to know all those implications
or find detailed tags on the object. I thought the OSM-way was
assuming as less implications as possible. Some time ago there weren't
even national borders which could have been used to determine which
jurisdiction you are in.


My intention was to point out, that good documentation and definitions
are IMHO needed or at least very helpful for interpreting the data. I
wouldn't mind if there were international equivalence lists for every
single tag. There are some other false friends btw., some time ago I
was advocating to tag an Italian bar as amenity=bar well knowing that
in Germany people would expect a different place when seeing a bar
than what they'll get in Italy. Still as all of the Italian Bars are
called "Bar" and as they are not really a cafe, tagging them as Bar
seems easiest to me. But you cannot make reliable assumptions whether
they sell tobacco or ice_cream as long as it is not tagged.

The same differences you get for petrol-stations: in Germany it will
be hard to find one that doesn't sell tobacco and beer, while in Italy
you would hardly find any that sells other than fuel. I agree that it
would be better to have a default-list about what to expect in which
context, instead of tagging hundreds of redundant tags to all objects,
still in particular cases like routing-relevant "highway" some
redundancy like foot=yes/no on cycleways IMHO is improving and
clarifying the situation.

...
> When you write you should make strenuous efforts to be not quite so
> patronising. :p

sorry, I didn't mean to, it's lack of knowledge / practise in
language, maybe I don't get the subtones of what I write.

cheers,
Martin




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