On 11/8/14 3:11 PM, Sarah Hoffmann wrote:
Postal towns is really a concept that wasn't taken into account when the Karlsruhe address schema was developped and IMHO doesn't really fit. I'd really like to see some discussion in the US community about how it can be tagged including considering the possibility to come up with a brand new way of tagging it. If you then come to the conclusion that addr:city is still the best way to go, so be it. But I'd be far more happy to support something in Nominatim that fits exactly the US situation than hack some European tagging system until it hopefully gives the right result most of the time. Kind regards Sarah (your friendly nominatim maintainer)
ok, here are some things to think about:
1) the Census Bureau has an area based version of zip codes (postal codes to the non-US types) called ZCTA. it is not a complete representation, it covers about 30,000 of the 50,000 unique zip codes, but it covers all the ones that can be reasonably envisioned as areas. 2) missing from ZCTA is the mapping from zip codes to "postal city" as you call it. there is more to it than just a many-to-one mapping, which i'll address in a minute. 3) most of the US mappers are opposed to importing this into OSM for a couple of good reasons, i'm one of those opposed. 4) however, there is also a movement in the US mapping community towards having certain types of data kept out of the core OSM database, including various types of admin boundaries. there are two projects looking at admin boundaries in this manner; i'm working on one of them. 5) so if we could 1) come up with the ZCTA->City mappings and 2) provide them in a convenient external database for use by geocoders, is this something that might reasonably be made use of in Nominatim? i've been considering what a project to crowdsource the zip->city mappings for the US might look like. currently the data exists in OSM to handle about 4% of the mappings, but a maproulette style challenge might get us a lot of the rest. as for that many to one mapping that isn't, basically, for each zip code there is a primary city and potentially a number of secondary cities. the primary city is the city name of the post office that serves the routes; the secondary cities are generally traditional place names within the delivery area; for example, for years i lived in the Lansingburgh neighborhood of Troy NY, and the post office would deliver mail for either city name. any effort to crowd source this data would need to take care of that detail. richard -- [email protected] Averill Park Networking - GIS & IT Consulting OpenStreetMap - PostgreSQL - Linux Java - Web Applications - Search _______________________________________________ Talk-us mailing list [email protected] https://lists.openstreetmap.org/listinfo/talk-us
