In February of this year I started a community effort to fix broken multipolygons in OSM and switch the remaining old-style multipolygons (with the tags on the outer ways instead of on the relations) to a more modern tagging. Seven months later I am declaring this effort to be finished.

The Multipolygon Fixing Effort started a few weeks ago is going well. An amazing amount of work has already been done, but there is a lot more to do. I have started a blog (sort of) specifically to document what is happening with that effort. See you there!

There are a lot of (multi)polygons in OSM that are broken in one way or another. And we have to fix them. While some of the broken ones appear on the map just fine, some don’t appear and some mess up the map. And some of those that appear fine on the main OSM map will not show up on other maps where different software is used.