Opened 8 years ago

Closed 7 years ago

#3679 closed defect (invalid)

Nominatim search returns unexpected results for many places in Southern California

Reported by: ponzu Owned by: geocoding@…
Priority: major Milestone:
Component: nominatim Version:
Keywords: Cc:

Description

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.

Change History (4)

comment:1 Changed 8 years ago by ponzu

Component: nominatimmapnik
Owner: changed from openstreetmap@… to mapnik-team@…

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?

comment:2 Changed 8 years ago by ponzu

Component: mapniknominatim
Owner: changed from mapnik-team@… to openstreetmap@…

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.

comment:3 Changed 7 years ago by Tom Hughes

Owner: changed from openstreetmap@… to geocoding@…

comment:4 Changed 7 years ago by datendelphin

Resolution: invalid
Status: newclosed

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

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