[OSM-talk] Post code areas

[Maarten Deen]

On Tue, 06 Apr 2010 14:52:47 +0200, Frederik Ramm <frederik at remote.org>
wrote:
> Hi,
> 
> Frederik Ramm wrote:
>>     we're thinking about importing post code areas in Germany. Are post

>> code areas being mapped in other countries already, and if so, using 
>> what tagging schema?
> 
> Thank you for the replies.
> 
> I have one last question. I believe that Germany is not unique in 
> sometimes using roads as post code boundaries, with houses on one side 
> having post code A, and houses on the other side having post code B.
> 
> Suppose that one were to create a multipolygon for such a post code 
> area; how should it be done?
> 
> Or turning the question around- if you looked at OSM data and you found 
> that two neighbouring postcode areas were using a road as their 
> boundary, would you automatically assume that houses on one side belong 
> to one and houses on the other side belong to the other? (If *all* 
> houses on the street belonged to one of the two post codes, then the 
> boundary could not be the street but would have to be offset a bit.)
> 
> Or is this something that would have to be tagged specially?

In the Netherlands, most roads have a different postcode on the two sides
of the roads if you take the complete postcode. Suppose the postcode is
1234 AB then 1234 is (a part of) a town and AB is (a part of) a road.
So the left side of the road (usually the odd numbers) has 1234 AB, the
right side of the road has 1234 AC.

I would assume that the boundary is just that: different postcode on
either side of the boundary, wherever that boundary is situated.

Regards,
Maarten