Nominatim search returns unexpected results for many places in Southern California

[openstreetmap-trac]

Reporter: ponzu
[Submitted to the original trac issue database at 5.18am, Wednesday, 13th April 2011]

I could list a number of specific instances of cities being listed as belonging to a wrong county (Santa Monica, Los Angeles, Beverly Hills and a number of other cities are listed as being in Ventura County - they should be in Los Angeles county) but I suspect there is a broader issue with the parent-child schema and/or tagging of places in Southern California.

Here's a search for Los Angeles: http://open.mapquestapi.com/nominatim/v1/search.php?q=los+angeles

I tried to summarize my findings here http://forum.openstreetmap.org/viewtopic.php?id=11945 if that helps. I just want to know if it's a bug in Nominatim, poor OSM data, or my understanding of how Nominatim is supposed to work is off. I'll be happy with any explanation.

[openstreetmap-trac]

Author: ponzu
[Added to the original trac issue at 8.50pm, Wednesday, 13th April 2011]

Since creating the ticket, I have gathered almost all pieces of the puzzle. The problem arises from the presence of county nodes (and city nodes as well) in addition to polygons. The problem for Nominatim is solved by removing the nodes. At the same time, this will cause Mapnik-rendered maps to lose county and city labels as Mapnik only renders names of place nodes.. The wiki-documented role=label on the boundary relation would solve this rendering issue, but it has not been implemented in Mapnik and reportedly works only so-so in osmarender. The question then becomes do I open a ticket for Mapnik to render county (and other administrative boundary) labels, or is it already in the works?

The second question: do I delete the county (city, etc.) nodes where polygons or relations exist, or do I wait until the rendering of labels is implemented?

[openstreetmap-trac]

Author: ponzu
[Added to the original trac issue at 7.26am, Saturday, 23rd April 2011]

I think I'll change it back to Nominatim. I have learned what the Mapnik plans are for rendering the place polygon labels, now I would like to hear how Nominatim can resolve such issues on their end.

[openstreetmap-trac]

Author: datendelphin
[Added to the original trac issue at 10.13pm, Tuesday, 28th February 2012]

The relation for 'Los Angeles County' is not closed
In order for nominatim to find the county reliably, it needs closed boundary relations

needs to be fixed in osm