I think two things are wrong here.
All Polish names are just a little bit North of the border. Ways seem to be off for about the same distance (judging by border disconnections). Either border is shifted South or everything else shifted North.
The other wrong thing is that the data source for Polish villages is prettyinaccurate, their positions are rounded to 0.2°, and this can’t be easily fixed.
Altogether there are about 40000 villages (out of 60000) whose coordinates still need to be adjusted.
Some of them (perhaps some 1/2) can be fixed using coordinates from UMP but the remaining bunch are not in UMP. I have a script to compare village names + coordinates + other info between UMP and OSM and adjust coordinates, should I run it on all of poland.osm? So far I only ran it on some regions.
I do not understand why one does not second a correction of about 10 km for about 20.000 villages. What is the reason for not wanting that? Or is the data in UMP not correct?
Edit: do I have to conclude that not only so many villages lay a 10 km off position but also all roads leading to them ???
Nope, the villages whose coordinates are rounded were imported from either GNS or Geonames a long time ago and afaik nothing else was imported so it’s only the vilages
Well, we surely can adjust all the villages to better fit UMP data, but some villages have better positions in OSM. That’s why it only makes sense where the villages are important for some reason.
In this case, the border seems to be off, and the villages are good enough. We could correct them, but it would not change much, they’d still be North of the border. That’s why I think we should get and verify some border data, and then import it. Any volunteers?
The script doesn’t touch villages that have ever been modified, only those that haven’t been moved since the 2007 import by user:devrise so their coordinates are rounded.
Only problem is where do we take it from
Maybe Russia has some official public data about their borders and we could load Kaliningrad Oblast southern border from there, guess I can ask on the russian list.