[Tagging] noexit=yes on ways ?

Florian Schäfer florian at schaeferban.de
Thu Apr 10 18:27:53 UTC 2014


Am 10.04.2014 16:59, schrieb Pieren:
> On Thu, Apr 10, 2014 at 4:26 PM, Florian Schäfer <florian at schaeferban.de> wrote:
>
>> True, in the most cases it is not important. But sometimes it is, for
>> example in my T-deadend example, mentioned on this ML.
>> All cases can be covered by the tagging on nodes. The tagging on ways can't
>> cover all cases (deadends with more than one end) and causes problems for
>> example when splitting ways.
> I also explained why the mentionned examples are not a problem. I'm
> ready to change my opinion if I get valid arguments...
As I have already pointed out, you have misunderstood my T-deadend example.
Let me explain it again:
Let's assume, we have a T-shaped deadend (entrance at the bottom). The 
crossbar is one single OSM-way, one end of this way is passable for 
pedestrians, the other is not passable for anyone. In this case the 
tagging on ways is insufficient, if you don't split the way.
>> Therefore I'd recommend in the Wiki to use it always on nodes to avoid the
>> problems with way-tagging.
> But we don't have "problems" with the tag on the way !
I see several problems with the tag on the way:
* It's unclear, which OSM-ways of a deadend street should be tagged. 
With nodes, this question can be clearly answered.
* What about splitting? Especially when you say, that only the very last 
OSM-way should be tagged. And consider that not every mapper is aware of 
noexit-Tags and how to use them.
* If all OSM-ways of a deadend-road should be tagged, what about 
deadends with multiple endings (some impassable, some not)

But these are in my eyes rather minor arguments, because we could solve 
them by defining rules for special cases and changing editors to deal 
with it correctly.
My main argument is:
Nodes are enough to describe _all_ the cases, where noexit=yes makes 
some sense, because the property you want to describe [1] is punctiform. 
It is a property of the _end_ of the highway, not the whole highway or 
the last part of it. A small, but important difference. So let's keep it 
simple and use only nodes. That is enough for _all_ situations and does 
not cause any problems as far as I know.
> It's true that the wiki has to document the best practices but it should not fordid
First of all, I don't want to forbid anything. I want to recommend the 
tagging on nodes to prevent mappers (esp. newbies) from tagging unclear 
or ambiguous, because they are not aware of special cases, where the 
tagging on ways is insufficient. So the tagging on nodes is a better 
practice than tagging on ways.
> practices that are not wrong, harmfull, unclear or ambiguous !
Surely the tagging on ways is not really wrong nor harmful, but it can 
lead to unclear or ambiguous tagging.
> I regret the time when people worked with a more open mind in this project.
In my eyes, openmindedness means to listen to the arguments of others 
without prejudices, trying to understand these arguments. But it does 
surely not mean to accept any other opinion.
I tried hard to understand every argument in this discussion as 
impartial as possible. I also responded, where I disagreed in some 
points, because I did not share the opinion. But in the end, I will 
accept any outcome. I would be happy, when tagging on ways would be 
recommended in the wiki, but I would be even happier, if it would be 
deprecated by the wiki.

An open project can't accept all opinions, because there are many 
contrary opinions. So some rules have to be defined. For finding those 
rules, all involved have to discuss and finally come to a consensus. I 
give my best to participate in the discussion and work for a consensus 
regardless what it is.

Cheers
Florian



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