Relation conflict OSM

Apr 18, 2013 at 7:03 AM
Edited Apr 18, 2013 at 12:19 PM
Hi,

When we are trying to edit or delete a line feature which is part of a route, we get the following error message:
“The feature (OSMID: …) you are attempting to delete is a member of relations (OSMIDs: …). If you continue, the editor will remove the feature from the relations, otherwise the delete operation will be undone.”

This error only occurs if we attempt to delete a line feature which overlaps with a route polyline, covering multiple line features. When editing line features that do not overlap with such route polylines, everything works as expected. However, we are unable to delete the route polyline which is related to the line we want to delete. It seems like there is no way to delete either of the features in a relationship, while we want to move a road which has been relocated.

Do you know what can be the cause of the error we are recieving, and how we can overcome this problem without messing up the OSM data structure?

Thanks in advance!

Regards, Edwin and Martijn

Image
Coordinator
Apr 19, 2013 at 12:24 AM
Hello Edwin and Martijn,
As you may know, the OSM data model is made up of nodes, ways, and relations (http://wiki.openstreetmap.org/wiki/Data_model). At a high level, the ArcGIS Editor for OSM tools translate this into points (nodes), lines (vectors defined by nodes and ways), polygons (ways that start and end at the same point), and a table that manages the relations. You can think of relations like this: if you have a road - e.g., a long motorway - part of a bus route may go from another road onto the motorway and then off again to another smaller road. This bus route can be defined with relations, as it doesn't represent a whole new feature but is a relation of segments on existing features...

So - in the ArcGIS Editor for OSM feature dataset, if you edit a line such that you are moving the line, the relation should stay with the feature and you shouldn't get an error. If you are deleting the feature and then want to recreate it, you will need to destroy the relation relationship first, which could be dangerous depending on what the relationship is - e.g., if it is a segment in a long bus route. Also, our Editor tool does not yet have a relation editor component for deleting, recreating, and editing existing relationships.

In either case it would be useful for us to replicate the behavior so we can log the issue. Will you send me the bounding coordinates of the area you have downloaded, and some of the OSM feature IDs for the features that cause the error when you move/attempt to delete them (I do see the screenshot you provided, but I can't read the details to replicate)?

Many thanks!

Christine
Apr 22, 2013 at 6:32 PM
Hello Christine,

Thanks for the quick reply. Due to a heavy weekend my reply took some time.

We downloaded a OSM from the Netherlands from download.geofabrik.de. In this OSM we found several related segments. One I can point out is a place in "'s-Hertogenbosch" at "De Parade" located at geo-point: 5,307 - 51,687 decimal degrees.

When I want to remove this line segment (or relationpath) it will produce an error as described before. When I move the line segment included the begin and end node it will give an error but it moves after I click OK.

The problem we're having is when we produce such error and ignore it, our converter to GarminMaps will gives some errors and it doesn't produce a map anymore because it misses things. Normally I should just ignore the places where it goes wrong but unlucky a few of the places need to be edited. That's why I came up with this question.

Is the a way to just remove all the relations? I fluched the relations table but I kept seeing relation path's in the map.

Thanks in advance!

Best regards,
Edwin and Martijn - the Netherlands
May 23, 2013 at 3:45 PM
Hi Christine,

Did you see a change to replicate our steps?

Martijn de la Cosine - the Netherlands