Hi Richard, Sam, Steve, Thanks for your feedback. I'll continue using PostGIS (good for my own skills as well), and look at the other suggestions you've made. I'll also leave the NIDs on the data which I will eventually upload. They don't hurt, although there is the theoretical possibility that due to subsequent edits they get shifted (splitting and joining).
I'll also investigate PostGIS buffering a bit more. 10 to 20 meters should be enough. In cases of roads which have been shifted 100 meters, they need better investigation anyways. In case they turn out to be drawn from low-res imagery, they can better be replaced by the Geobase data. Hopefully the buffering won't cause data to be removed accidentally. For areas where the OSM density is quite small (as in my test areas) it is no big deal to remove duplicate Geobase roads manually. Better to be safe than sorry. How would RoadMatcher deal with a case where two roads are aligned, but one of them has been shifted? With regard of this I also think a manual step should always take place. (Maybe even to evaluate discarded data.) We must only make sure that it covers those parts which can't be done automatically, so the required amount of time spent of it is as small as possible. Our brains can still make judgments better than the computer. I don't think anyone has very sophisticated algorithms which eliminate human input in the process ;) I hope to really start with the Geobase import soon. I came across the Global Administrative Areas (GADM) database, which is part of the BioGeo project mentioned at the potential datasources. I've looked more closely at the data, and exchanged some ideas about the import of this data as administrative boundaries with the guys on #osm-nl. (Sorry, sometimes it's necessary to chat in my mother language ;)) I also inquired after use of the data by OSM, because of their copyright (CC-BY-NC-SA 3.0), and because they aggregated data from various other sources. Regards, Frank _______________________________________________ Talk-ca mailing list Talk-ca@openstreetmap.org http://lists.openstreetmap.org/listinfo/talk-ca