If I type a street and town into the search box on the map page the nominatim finds the place on the map correctly but says that the street is in a nearby suburb which is incorrect.

To fix this I have drawn a polygon and named it. This should contain it to its own area but it does not always work. Some mappers think the single node suburbs are the problem. Please try some address in your area for examples. There is also a delay as the nominatim is not being updated at the present time. What are your solutions or ideas on this problem. Note examples are now fixed

Edit (extracted from comments):

One example: http://www.openstreetmap.org/?minlon=-0.171881511807442&minlat=52.3324775695801&maxlon=-0.164698585867882&maxlat=52.335319519043

This is Hartford Road, Huntingdon, which appears as part of Stukeley Meadows(which is a polygon), whereas Stukeley Meadows is a suburb of Huntingdon. The name also appears in Godmanchester as well.

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asked 13 Jun '11, 22:42

andy%20mackey's gravatar image

andy mackey
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edited 18 Jul '12, 11:56


To fix this I had to drawn a polygon and name it. This should contain it to its own area but it does not always work.

This is the key to the problem. Drawing a polygon around a node does not "contain" the node area. Nominatim treats this as two boundaries, one bound by the polygon, and one by the node.

The node area is then estimated, since Nominatim does not have a bounding polygon for it. It makes estimates, and it's often wrong.

If you have a bounding polygon, then you can remove the node. Removing the node should fix your problem once Nominatim comes back online (it's not updating at the moment due to scaling issues discussed in other questions).

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answered 20 Jun '11, 19:18

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emacsen
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edited 09 Sep '14, 19:21

andy%20mackey's gravatar image

andy mackey
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If you have questions about Nominatim search results, Nominatim lets you see how it reached its conclusions.

To see it, do your search on http://nominatim.openstreetmap.org/ . In the result list, click on "details"; then you'll see exactly how Nominatim reached its conclusions.

In your example, searching for "hartford road, huntingdon" on Nominatim will show you that the OSM DB contains a node called "Stukeley Meadows" ( http://www.openstreetmap.org/browse/node/280778644 ).

This node is tagged as place = suburb, and Nominatim apparently automatically considers all objects in the vicinity of a place node to be part of that place. This is probably a heuristic for cases where there is no poylgon for a place.

In this case, as a Nominatim search for "stukeley meadows" shows, there are two objects named "Stukeley meadows": A node tagged place=suburb (see above), and a polygon ( http://www.openstreetmap.org/browse/way/112836767 ). The latter is probably the polygon you made.

In this case, I believe the best solution is to delete the place node (as the polygon you made is more precise). Then Nominatim should no longer consider Hartford Road to be in Stukeley Meadows.

And BTW, please fix the capitalization of the name in the tags of your polygon :-).

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answered 20 Jun '11, 16:43

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sleske
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thanks sleske for nominatim link I've not used that before.I've heard nodes are required to get place names rendered. ponzu as raised this problem http://trac.openstreetmap.org/ticket/3679 . ideally the nominatim would not give a radius for a place of some unknown size (to me) maybe adjacient polygons will shut out other suburbs I try that out

(20 Jun '11, 19:22) andy mackey
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question asked: 13 Jun '11, 22:42

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last updated: 09 Sep '14, 19:21

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