OSM Postcode Mapping for SL4 1 Postal Sector

The circles on the map above are the postcode unit 'centriods' from Code-Point Open, under the Open Government Licence. The 'centriod' is calculated by taking the average of the coordinates of all the delivery points with that postcode, and then snapping that location to the nearest delivery point in that postcode. The data may be freely used in OpenStreetMap, but please make sure you understand it first. Also please only add postcodes to objects representing addressable entities; do not add the postcode centroids as themslves. Suggested source tag code-point_open

The circles are coloured by whether or not there is at least one OSM object with that value in its addr:postcode tag. Click on a point to see the postcode. The numbers in brackets are the number of OSM objects with that postcode.

The centroids are the location of the nearest 'delivery point' to the arithmetic mean of the coordinates of all the delivery points within that unit. Those points with a codepoint PQI greater than 40 are excluded from the map above. (Higher values are typically not geographically accurate. In particular, PQI=50 is used for new postcodes before the location has been determined. The location given for such postcodes seems to be derived from other existing postcodes with similar units letters, which may not be close to the new postcode.)

The pale blue lines from the circles join each Code-Point Open centroid to the mean coordiantes of all the OSM objects with that postcode. (For ways an relations, the centre of the rectangular bounding box is used at the coordinates for the OSM object.) Long lines may indicate missing or incorrect OSM objects for that postcode. In particular, if all the postcodes in a givne unit are correctly mapped, the circle should be located on the nearest delivery point within that postcode to the other end of the blue line.

The OSM data for the number of objects with each unit is usually updated once a day at about 10:15 UTC, with data from about 20:30 UTC the previous day. The data used to compute the OSM mean position is updated less frequently, usually about once a week.

All units within this sector:

Units with street mismatches in this sector: