[Tagging] noexit=yes on ways ?

André Pirard A.Pirard.Papou at gmail.com
Tue Apr 8 14:20:38 UTC 2014


On 2014-04-04 17:35, Pieren wrote :
> On Fri, Apr 4, 2014 at 4:14 PM, Nelson A. de Oliveira <naoliv at gmail.com> wrote:
>> On Fri, Apr 4, 2014 at 10:54 AM, fly <lowflight66 at googlemail.com> wrote:
>>> If it is accepted, I gonna hange the wiki accordingly and gonna ask a
>>> for validator checks in JOSM, as we have more than 100,000 ways with
>>> this tag.
>> Basically I agree with the current text of
>> http://wiki.openstreetmap.org/wiki/Key:noexit (except that I don't
>> agree to use it on ways).
> As I understood, the "noexit=yes" means "this way is a cul-de-sac".
> What is unclear if the tag is on the last node or on the way itself ?
> It is still a cul-de-sac...
>
> It seems that 40% of the "noexit=yes" tags are on ways and are
> understandable by their contributors but 100% of the persons writing
> on this thread do not understand what 40% of the contributors do ...
> So, instead of trying to change 40% of the contributors with wiki
> fiddling and josm obscure validations, you should try to open a bit
> your mind and accept that contributors can supply the same information
> in different ways (or nodes ;-). Stay open like "Open"StreetMap ;-)
In the survey I made before, I tried in vain indeed to understand what
the contributors mean with most of the noexit=yes tags they add.  A dead
end is, at either end of a way, a node that is not connected to any
other allowed or usable way. It's quite visible on any map and it's what
the GPS routers understand the best. What's the use of adding noexit=yes
that do not show on the map and that the routers ignore?

Here are some noexit=yes on nodes
<http://overpass-turbo.eu/map.html?Q=%3C%21--%0AThis%20has%20been%20generated%20by%20the%20overpass-turbo%20wizard.%0AThe%20original%20search%20was%3A%0A%E2%80%9Cnoexit%3Dyes%E2%80%9D%0A--%3E%0A%3Cosm-script%20output%3D%22json%22%20timeout%3D%2225%22%3E%0A%20%20%20%20%3Cquery%20type%3D%22node%22%3E%0A%20%20%20%20%20%20%3Chas-kv%20k%3D%22noexit%22%20v%3D%22yes%22%2F%3E%0A%20%20%20%20%20%20%3Cbbox-query%20s%3D%2250.618538570096796%22%20w%3D%225.619184970855713%22%20n%3D%2250.62584897418278%22%20e%3D%225.632467269897461%22%2F%3E%0A%20%20%20%20%3C%2Fquery%3E%0A%20%20%3C%21--%20print%20results%20--%3E%0A%20%20%3Cprint%20mode%3D%22body%22%2F%3E%0A%20%20%3Crecurse%20type%3D%22down%22%2F%3E%0A%20%20%3Cprint%20mode%3D%22skeleton%22%20order%3D%22quadtile%22%2F%3E%0A%3C%2Fosm-script%3E>.
Why are a few dead ends tagged and the others generally not? What is its
meaning at the steps <http://www.openstreetmap.org/way/239040172>?  That
cars cannot use the steps or that it's a dead end for pedestrian too?
What does it mean in the middle of rue des Crahlis
<http://www.openstreetmap.org/way/58297735>? That the main street cannot
be reached from the end or the opposite? Etc.

Here are some noexit=yes tags on ways
<http://overpass-turbo.eu/map.html?Q=%3C%21--%0AThis%20has%20been%20generated%20by%20the%20overpass-turbo%20wizard.%0AThe%20original%20search%20was%3A%0A%E2%80%9Cnoexit%3Dyes%E2%80%9D%0A--%3E%0A%3Cosm-script%20output%3D%22json%22%20timeout%3D%2225%22%3E%0A%20%20%20%20%3Cquery%20type%3D%22way%22%3E%0A%20%20%20%20%20%20%3Chas-kv%20k%3D%22noexit%22%20v%3D%22yes%22%2F%3E%0A%20%20%20%20%20%20%3Cbbox-query%20s%3D%2250.66839555058174%22%20w%3D%225.717890262603759%22%20n%3D%2250.67569820203223%22%20e%3D%225.731172561645508%22%2F%3E%0A%20%20%20%20%3C%2Fquery%3E%0A%20%20%3C%21--%20print%20results%20--%3E%0A%20%20%3Cprint%20mode%3D%22body%22%2F%3E%0A%20%20%3Crecurse%20type%3D%22down%22%2F%3E%0A%20%20%3Cprint%20mode%3D%22skeleton%22%20order%3D%22quadtile%22%2F%3E%0A%3C%2Fosm-script%3E>.
What information do they bring? At which end of the ways is the dead
end?  And, if the answer id "it's obvious" why is an obvious thing
highlighted?  Why is Chienrue and many others not dead ends? Why is this
segment <http://www.openstreetmap.org/way/91796014> and the others a
dead end? Is it impossible to go round the loop? Why is this a dead end
<http://www.openstreetmap.org/way/92843940> and not the stub on the
left?  Etc.

Those tags are constant riddles.  Yes, please help us understand.
Now, regarding JOSM and Osmose validations, it's not clear what
obscurity you speak about. 
More usage instructions
<http://wiki.openstreetmap.org/wiki/Talk:Key:noexit#More_usage_instructions>
to which I added a link explains a very clear experiment showing that
JOSM and Osmose make a "way ending near an other way" sanity test and
the noexit page is very clear that the purpose of noexit is to mute that
test (telling that there is no tagging problem). That's the meaning of
noexit, not to tag dead ends generally.
Unfortunately,
1) The noexit page used to say
"Use the noexit at the end of a highway to indicate that there no
possibility to travel further ..."
when the meaning is in reality
"... *on the node* at ... to indicate when doubtful *that the
impossibility* to travel further ... *is perfectly normal*, ...".
2) contributors used to read only that phrase, not the full explanation
below it, and tagged a useless noexit condition instead of only
confirming doubtful dead ends that are now impossible to spot in the
noexit mass
3) others do "similar and inventive" tagging as I describe next, looking
like other tagging or "better", including noexit traffic signs not
telling where the blocking occurs, not even in what direction it is.

The least that can be said is that the rules of noexit=yes were hard to
read and not respected.
I hope this improved a bit.

I'm in despair because I often read that the wiki is not important,
because it's often ambiguously stated, because contributors say that no
votes are needed, that they can tag as they feel it, even vandalize
other tags, just keeping an eye on what the others are doing and
discussing among themselves.  This is particularly harmful regarding
routing (GPS).  Contributors say that the public laughs at the detours
of OSM users, I corrected many mistakes letting cars go where they
shouldn't, I even was scolded for correcting obvious mistakes on the
wiki, OSM users laugh at themselves and I was even laughed at for saying
that OSM routing is important.

The worst is in statements from the Walloon Government, saying,
regarding a possible cooperation or  exchange of data with OSM, that OSM
may not be up to their requirements for data quality.

Cheers,

André.



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