Extract relations with all members in an area

Question

Is there a way to select a relation with all of its members belonging to a specific area?

I'm currently working with hiking routes and I want to store all the hiking tracks for a given input area. As far as I understand from the docs, even if a relation has only one member in the selected area it will be included. Is there any simple workaround to avoid that?

Here is a basic example, any suggestion would be much appreciated. I'm quite new to OSM and OverpassQL, sorry in advance if this is elementary stuff.

Accepted Answer

1

One approach is to use around:0 to detect where routes cross the members of the query area. Proof of concept: http://overpass-turbo.eu/s/1812

I didn't look at the output to see if it was entirely correct, but it at least goes in the right direction. I'm not sure if it would work to use the relation as one of the inputs (using the member ways ensures that only intersections with the boundary are considered; it may work the same with the relation as the input).

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answered 01 Jun '21, 22:57

maxerickson
12.7k●10●83●176
accept rate: 32%

This seems to work fine, it becomes quite heavy scaling the boundaries up to provinces but keeping admin_level=8 results are good even in terms of time. I've perfomed some tests with cities full of hiking routes and also with cities that shows no routes at all, results seems correct in both cases. Thanks a lot!

(02 Jun '21, 01:09) Debo790

Answer 2

1

area[name=Spoleto][admin_level=8]->.Spoleto; //Search Area
rel(pivot.Spoleto)->.Bound; //convert to way to render
.Bound out geom;
(
rel[route=hiking](area.Spoleto)->.Within; // All hikes within search area
-  
rel .Within(around.Bound:0); //Remove those which cross boundary
);  
out geom;

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answered 04 Jun '21, 21:32

DaveF
3.3k●84●98●133
accept rate: 16%

This now retrieves the correct results, but it doesn't check for multiple cities (e.g. Milano or Roma). The code provided in the question (and in answer of maxerickson) deals with it using this: https://help.openstreetmap.org/questions/64305/overpass-api-get-city-boundaries-within-a-country-slow-query/70342

Obviously this decreases performances, but it's the best I came up with so far. Thanks for your effort anyway, your solution is the way to go when dealing with cities with no homonyms.

(05 Jun '21, 09:15) Debo790

Answer 3

0

The nearest I've ever been able to trim to a boundary is to Recurse down to the way members & then search within the area, but this includes ways which overlap the boundary.

area[name=Spoleto][admin_level=8]->.Spoleto;
rel[route=hiking](area.Spoleto);
way(r)(area.Spoleto);
out geom;
rel(pivot.Spoleto);
out geom;

PS I wish OP had a global area option similar to bbox. It would save a lot of typing.

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answered 03 Jun '21, 16:56

DaveF
3.3k●84●98●133
accept rate: 16%

This is actually faster, but it includes ways relations that shouldn't appear. An example is in the comment above the query: http://overpass-turbo.eu/s/185E The aim is to find relations with all the members inside the given area, if some of those members are outside then the whole relation should be discarded.

(04 Jun '21, 00:18) Debo790

Extract relations with all members in an area

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