On 27 May 2007, at 16:51, Mike Collinson wrote: > At 01:44 PM 26/05/2007, David Earl wrote: >> I have been wondering about postcodes. We have a postal_code tag >> which can >> be applied to streets and it would be nice to collect these. >> However it is >> not something like name plates that you find in the street by >> observation. >> There are about 2 million postcodes in the UK, so gathering them >> manually >> via the freethepostcode project is hard. But using data from most >> other >> places is subject to copyright. > > Answering David's posting very obliquely, how close are we in the > current search engine(s) to being able to geodecode at the postal > district level? (i.e the LS21 part of LS21 3LW; 3,094 districts > [http://en.wikipedia.org/wiki/UK_post_codes]). This would be a > more modest and achievable interim goal and useful for searching > features in a roughly 5-10km radius. Good enough at least for now?? > > Also, as a full post code is a postman's route, it is very possible > that many streets straddle more than one full post code so it may > not make sense to tag it as such - I've no proof of that so far.
Post codes can cover anything from a single house to a whole street or business park. However it is more common to have longer streets have many post codes. Where I used to stay had 105 as the max house number on the odd side and 72 on the even side of the street. The street had 4 different post codes. > > In my short UK experience so far, postal districts are much easier > to determine than full post codes as (all?) villages and at least > smaller towns lie within one such area, so you just need to find > out one representative address for an area. The freethepostcode > project may also already have at least one known point per > district. West Yorkshire councils also kindly put them on street > signs, so better boundaries can be determined over time if folks > would add a postal_code= tag to a random set of streets in each > area they map in. The main parts of post codes are often bounded by main roads, thus making them easy, if you know the boundaries. [...] Shaun _______________________________________________ Talk-GB mailing list [email protected] http://lists.openstreetmap.org/cgi-bin/mailman/listinfo/talk-gb
