Thanks Fredrick and Katie,<br><br>Yes, this is how US ZIP (postcodes)
work as well. I'm not a web programmer, but I assume most of the
post-code based geolocation that websites use work off of a centroid
and distance-vector approach. I agree that ZIPs are very useful for
one-way geocoding, but not so useful for reverse geocoding, which is
what I think Mike wants to do.<br>
<br>Mike,<br><br>If you're looking for administrative boundaries to
split your regions on, I believe all of the county boundaries have been
imported from the 2010 US Census data at this point.<br><br>Have fun,<br><font color="#888888">Chris</font><br>
<br>On Sun, Dec 20, 2009 at 3:34 PM, Frederik Ramm <span dir="ltr"><<a href="mailto:frederik@remote.org" target="_blank">frederik@remote.org</a>></span> wrote:<br>
Hi,<br>
<div><br>
Anthony wrote:<br>
> No. Zip codes do not represent geographic regions. They should not be<br>
> in a the map data, but in a separate database.<br>
<br>
</div>If I may chime in from the other side of the pond. Here in Germany we<br>
have post codes as well (hear, hear) and they are, theoretically, an<br>
artifact used for mail delivery, just as I gather from some of your<br>
postings. Some post codes are used for PO Boxes exclusively, and<br>
entities with large mail volumes can even get their individual post code.<br>
<br>
Still, the post codes are *commonly* used as a shortcut geo reference;<br>
it is a very popular way of doing e.g. a store finder on a web site -<br>
enter your post code and we'll show you the nearest store. Because of<br>
this, there is high demand for post codes to be available in OSM and I<br>
am certain that we will eventually either map or import them. (Not as<br>
administrative boundaries of course.) It is also not unusual to have<br>
choropleth maps built on top of post code areas, even though they suffer<br>
the same shortcomings here that Katie mentioned.<br>
<br>
I don't know if your zip codes are used in the same fashion. If they<br>
are, and if you have reason to believe that potential errors can be<br>
fixed by people on the ground, then I'd say it makes sense to have them<br>
in OSM. If, on the other hand, your zip codes are not really used as a<br>
geo reference, or if you think it is unlikely that the data can be<br>
maintained by ordinary people, then I'd leave it out.<br>
<br>
Bye<br>
Frederik<br>
<font color="#888888"><br>
--<br>
Frederik Ramm ## eMail <a href="mailto:frederik@remote.org" target="_blank">frederik@remote.org</a> ## N49°00'09" E008°23'33"<br>
</font><br>