This is somewhat off-topic for mkgmap, but I was thinking that perhaps WanMil or someone else has worked on something similar. I got some boundary data. I converted a tiny part of it from Spatialite to *.osm polygons with a self-made Perl script. There were some errors in the data, such as nodes very close to each other, or some boundary had one point less than the adjacent boundary. I fixed these in JOSM, by merging the too close nodes, or adding the missing nodes to boundaries. Already this was a considerable amount of work, because JOSM seems to lack a validator test for "nodes too close to each other" when they belong to different ways. Now, the next step would be to split these polygons (circular ways) to boundary relations. Each polygon would have to be split to way segments, and duplicate way segments should be removed. Then, relations should be formed from the way segments for each area. Is there any software or algorithm for doing this? Best regards, Marko