I'm trying to extract relations from Openstreetmap, using the Overpass Turbo service, saving as a KML file to be viewed on a suitable mobile phone app. I need the resulting KML to have simple geometries for it to work properly on the mobile app.
Relations in OSM can have multiple geometries (e.g. more than one polyline within one relation). An export of data, extracted from OSM using the Overpass-Turbo service, respects this. So the raw KML will be structured like this:
Proper GIS software should be able to cope with this. But KML files are increasingly used for viewing on mobile apps, which may expect the kml file to contain only single polylines. The app 'Maps.me' for example, displays such multi-polylines without gaps between what should be separate parts of the polyline (often making a real mess).
What would be the simplest way to extract data like this from OSM using Overpass, if we need to convert such multi-geometries into simple polylines (or polygons etc) so that they display on less sophisticated apps correctly? Obviously one solution is to bring data into GIS software, using this to manipulate the data, but I'd prefer a solution which avoids the use of GIS software completely. I was aiming to distribute an Overpass-Turbo query to a small number of non-GIS using colleagues, enabling them to use this to extract specific data from OSM themselves to view on their own mobile phones.