[Tagging] Multi-value tagging and Lane Groups

Colin Smale colin.smale at xs4all.nl
Wed Feb 8 20:16:27 GMT 2012


On 08/02/2012 20:25, Martin Koppenhoefer wrote:
> 2012/2/8 Colin Smale<colin.smale at xs4all.nl>:
>> On 08/02/2012 16:00, Martin Vonwald wrote:
>> question of syntax rather than concept. What triggered my post was actually
>> a comment by Martin K who also felt a need for multi-value tags (i.e.
>> arrays) in the context of the floors within a building.
>
> I think you got me wrong there, I was actually against the proposed
> form of multiple k/v-pairs stuffed all in the value for one key. For
> the building floors we can do this with several k/v-pairs (each for
> one floor or maybe range of floors) to keep tagging in a way it works
> with our established tools.
That's how I understood what you were saying, and I agree. Your example:

building:level:0:use=restaurant
building:level:1:use=residential

...definitely looks very similar to my example for lanes:

lanes:1:access=no
lanes:1:psv=yes



>
> The lane-case is a little different though, because if you have
> multiple values there (plus a definition from where to start) you
> won't need lane numbering. For buildings you will have unambigous
> numbers for the floors anyway, and they are the usual way to identify
> levels in buildings, but nobody says "take lane 3".
Actually lane numbering is in fairly widely understood in the UK, 
originating with the "authorities" - resulting for example in traffic 
announcements saying "there's a broken down lorry in lane 1" or "lanes 2 
and 3 are closed". It's certainly not a difficult concept to grasp. 
Lanes lie next to one another in order without overlapping, and floors 
do the same in the vertical direction. Floor "numbers" for human 
consumption in buildings are really only labels (not always numeric), 
and conventions vary. The first floor in the US is what we the ground 
floor, so their second floor is our first. Think of the buttons in a 
lift. It's common to skip the 13th floor in the US as well. So a 
building has physical floors, which have logical labels, and align with 
the terrain in a certain way, and have a certain vertical position 
relative to a datum. To me, the "height" of a floor is the distance from 
the floor surface to the surface of the floor above, and the height of a 
building would be the height of the bit sticking out above the ground 
(i.e. basements are not included.) The vertical position w.r.t. a datum 
might better be called the "elevation". The elevation of the most 
practical local datum is likely to be defined by the local cartographic 
powers-that-be (e.g.Ordnance Survey, Kadaster) and not WGS84.

Colin




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