[Tagging] Removing name_1 and alt_name_1 from Wiki
Tijmen Stam
mailinglists at iivq.net
Sun Jan 24 10:41:29 UTC 2016
Coming back to the lanes-example:
The turn:lanes tag is there to show what direction a lane turns (or,
akin to "map what's on the ground" principle: what arrows are drawn on
the road).
Say you have a junction in the motorway where three lanes continue and
two lanes turn off. I have seen situations where this is drawn on the
road with (from the left) two lanes with no arrows, one lane with a
straight arrow, then a block line, then two lanes with a right arrow.
This could be mapped as:
turn:lanes=none|none|through|right|right
The difference with
turn:lanes=||through|right|right
is that in the first example it is made explicit that there are NO
arrows on the leftmost two lanes.
With maxspeed in OSMAND: if I drive on a way with no maxspeed, the
maxspeed icon disappears, while driving on a German motorway, the
maxspeed icon actually reads "none". (Sadly, my car can only go 125 km/h)
On 24-01-16 11:12, Gerd Petermann wrote:
> I don't think so. Where do we need null values in OSM?
>
> As you said, maxspeed=none means something like maxspeed=unlimited.
>
> I can't think of any tag key which should be stored in OSM with a null
> value.
>
> In what case would that add valud information compared to having no such
> tag ?
>
>
> Gerd
>
>
> ------------------------------------------------------------------------
> *Von:* Colin Smale <colin.smale at xs4all.nl>
> *Gesendet:* Sonntag, 24. Januar 2016 10:58
> *An:* Tag discussion, strategy and related tools; Tijmen Stam
> *Betreff:* Re: [Tagging] Removing name_1 and alt_name_1 from Wiki
> At present the string "none" is actually a value, the interpretation of
> which is specific to the key "maxspeed" . Maybe we should promote it to
> the equivalent of NULL in SQL.
>
>
> On 24 January 2016 10:43:16 CET, Tijmen Stam <mailinglists at iivq.net> wrote:
>
> With the value "none"
>
> For example on German Autobahnen, where you can drive as fast as you
> want is "maxspeed=none" which is different from having maxspeed not set:
> this means maxspeed is unknown or not tagged yet.
>
>
>
> On 20-01-16 09:06, Colin Smale wrote:
>
> Exactly.
>
> If a missing value (i.e. use the default) is not the same as
> explicitly
> having NO value, how do you override the default with "no value"?
>
> --colin
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