[Tagging] Fwd: Door to door routing to buildings with multiple occupants

Friedrich Volkmann bsd at volki.at
Tue Dec 4 11:18:17 GMT 2012

Pieren <pieren3 at gmail.com> wrote:
> One principle I like in OSM is "one feature, one OSM element":
> http://wiki.openstreetmap.org/wiki/One_feature,_one_OSM_element

An address is not a feature. An address is an attribute of a feature.  
An address never exists on its own in the real world. There cannot be  
an address somewhere in no man's land. It always refers to some  

> A single address should be tagged only once. If you have several POI's
> with the same address, tag the address on its own node.

This is not how mappers usually handle this case. They set the address  
on each POI, because otherwise applications cannot find out which POI  
has which address.

> The node does
> not have to be be "floating" but can be attached on the building way,
> either on the building entrance or where post boxes are physically (or
> vitually).

There are many possibilities where to put the node, but each of them  
has some cases where it won't work, and there are always arguments and  
edit wars about this. This is because each of the position is only  
part of the truth. The whole truth is that an address is actually an  
attribute of a 2- oder 3-dimensional object.

> Then it is to the software consumers to find the nearest
> node address when they search information about a specific POI.

The nearest node may not be the right one. E.g. the nearest node may  
be the address node of the next house. Or it may even be a node on the  
other side of
the street!

And not to mention that this won't do it for multiple addresses.

Friedrich K. Volkmann
Davidgasse 76-80/40/10, 1100 Wien, Austria

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