Existing building (and other features) that are incorrectly mapped

Im in the process of mapping my small town, however, there are some features (building shapes, running track etc.), that appear to have been automatically populated at some time as they as scattered all over the place, a running track at a school is has now moved 500m away from the currently mapped location.

Ive added hundreds of new buildings and added their street address over the last month, these seem to be gradually filtering onto other websites and apps, but the incorrectly mapped items are still present and dont seem to have been updated.

How is the process of existing building and objects handled when newer, correctly mapped objects are added?


By you spotting that they’re wrong, & fixing them! :grinning:

OSM relies purely on the efforts of it’s volunteer mappers, such as yourself :+1:, to first add things, then update them over time. There is no automated process to do so.

So if you’ve spotted something that you’re sure is wrong, please correct it’s outline, move it to the correct spot, or do whatever else is required to bring it up to date!

Good luck & have fun! :smiley:

PS If you’re unsure about anything, or need advice as to the best way to do it, please ask, probably back in this thread will be a good spot!

For the most part, all changes (adds, deletes, changes) propagate together. There are some exceptions, such as coastlines, and I think relations. However, different zoom levels tend to refresh independantly, so your change may show up at one zoom level, but not another. Finally, different tile servers/styles and apps refresh at different rates.

Could you let us know the location in question?

I would just like to note that imagery alignment can be quite a bit off and varies between updates. If you have a decent number of GPS traces or a suitably licenced cadastral layer it’s recommended that you tweak the imagery offset to match the more trustworthy data.

It’s possible that older map data was mapped to a different set of imagery.

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I get that part, what im referring to is the older data (>2 years) doesnt seem to get deleted from ‘other’ websites using OSM data, its a combination of the new data AND the old data.

For example on ‘windy’ the running track is in the old location, like they are using an outdated OSM source?

how to I share the location here?

It’s possible?

While changes update on OSM almost immediately, it’s up to each other company that uses our data as to when they update their background map. Somebody like Windy, who is worried about weather, not so much what’s on the ground, may possibly not update for years?

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Just copy & paste the URL address of OSM screen that you’re looking at e.g. OpenStreetMap (picking a random spot in Canada!)

Right, that makes sense.

Before I started a few weeks ago the town was pretty much bare and hadn’t been updated for a long time, but some of the house shapes are all over the place, probably because of the thick tree canopy the lidar couldnt penetrate?

I see the original post has a screenshot of AllTrails. They use Mapbox for their maps, as do many other apps and websites.

The city I live in has partial OSM coverage for buildings, and what I’ve noticed is…

  • When OSM building outlines are available, Mapbox does use them (but only after a significant delay, on the order of months).
  • If building outlines are missing from OSM, they fill in the gaps using low-quality outlines from a different source (presumably AI generated).

So as the months pass by, you should notice the low quality building outlines gradually get replaced by your OSM ones (in Mapbox maps).

Other providers could have different approaches of course. Perhaps some of them are doing a bad job of conflating features from different data sources, resulting in the duplicates you’re seeing.