[Geocoding] [OpenStreetMap] #5271: Wrong city tagging in NL due to admin_level difference

[OpenStreetMap]

#5271: Wrong city tagging in NL due to admin_level difference
-------------------------------------------------+-------------------------
 Reporter:  sander.vantulden@…                   |      Owner:  geocoding@…
     Type:  defect                               |     Status:  new
 Priority:  minor                                |  Milestone:
Component:  nominatim                            |    Version:
 Keywords:                                       |
  boundary:administrative,admin_level,city,village|
-------------------------------------------------+-------------------------
 Hi,

 I found some roads in The Netherlands that have the wrong city associated
 with them. For example, if you take a street in the village called
 "Malden",
 [http://nominatim.openstreetmap.org/search?q=jonckherenhof&format=json&addressdetails=1
 &accept-language=nl Nominatim returns] the corresponding village to be
 "Heumen", which is the '''municipality''', but not the '''village'''.

 It took me some time, but I think I found what could be the reason for
 this mistagging. In The Netherlands, the admin_level for '''city'''
 boundary is '''10''' and the '''municipality''' boundary is '''8'''
 ([http://wiki.openstreetmap.org/wiki/Key:admin%20level?uselang=en-
 US#References see here] for an explanation). This seems to be the other
 way around  for other countries.

 [https://www.openstreetmap.org/relation/409476#map=13/51.7811/5.8116 Here]
 is the "Heumen" '''city boundary''' relation (which holds the correct
 municipality boundary) and
 [https://www.openstreetmap.org/relation/2725495#map=14/51.7713/5.8403
 Here] is the "Heumen" '''suburb boundary''' relation (which holds the
 correct city boundary)
 [https://www.openstreetmap.org/relation/2725496#map=14/51.7894/5.8535
 Here] you can see that "Malden" also has a '''suburb boundary''' (which
 holds the correct city boundary). Because of the admin_level 10,
 "Heumen"'s admin_level 8 overrides it, to let it get the "Heumen" village
 tag.

 Does this problem I describe make sense? Are country-specific admin_level
 tagging already handled in Nominatim? Or would it be possible to add it
 for specific countries?

 This may be related to #5185, but I am not sure.

--
Ticket URL: <https://trac.openstreetmap.org/ticket/5271>
OpenStreetMap <http://www.openstreetmap.org/>
OpenStreetMap is a free editable map of the whole world