Thanks Fredrick and Katie, 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.
Mike, 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. Have fun, Chris On Sun, Dec 20, 2009 at 3:34 PM, Frederik Ramm <frede...@remote.org> wrote: Hi, Anthony wrote: > No. Zip codes do not represent geographic regions. They should not be > in a the map data, but in a separate database. If I may chime in from the other side of the pond. Here in Germany we have post codes as well (hear, hear) and they are, theoretically, an artifact used for mail delivery, just as I gather from some of your postings. Some post codes are used for PO Boxes exclusively, and entities with large mail volumes can even get their individual post code. Still, the post codes are *commonly* used as a shortcut geo reference; it is a very popular way of doing e.g. a store finder on a web site - enter your post code and we'll show you the nearest store. Because of this, there is high demand for post codes to be available in OSM and I am certain that we will eventually either map or import them. (Not as administrative boundaries of course.) It is also not unusual to have choropleth maps built on top of post code areas, even though they suffer the same shortcomings here that Katie mentioned. I don't know if your zip codes are used in the same fashion. If they are, and if you have reason to believe that potential errors can be fixed by people on the ground, then I'd say it makes sense to have them in OSM. If, on the other hand, your zip codes are not really used as a geo reference, or if you think it is unlikely that the data can be maintained by ordinary people, then I'd leave it out. Bye Frederik -- Frederik Ramm ## eMail frede...@remote.org ## N49°00'09" E008°23'33"
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