Sources to use in Sweden

Hello community,

May I ask you what is the best and/or most reliable source/s to capture (modify, edit, add, remove) the following features/layers:

  • Buildings
  • Road Geometry

Thank you,

For roads it’s the national road database (NVDB). To just see the roads alignment, the easiest way is to tick the “Trafikverkets vägnätverk” box in ID.

For buildings there are no really good avaliable sources as far I know. Use the best aerial photo and align it using NVDB.

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Anders already knows this, but for an international audience, it is worth noticing that

thank you Anders

thank you @turepalsson

I think worth adding to the discussion is that in many places of Sweden the landscape is hilly and the alignment of Bing satellite imagery is quite poor.

I’ve seen a lot of building edits by Tomtom users in northern Sweden that are poorly aligned, so I’ve spent a lot of time recently moving buildings to more correct positions when I’m working with the NVDB import project (actual manual merging, no automated import). I would like to see Tomtom users and others take more care about alignment. It’s not that hard and it improves the mapping quality a lot, and reduces correction work required by those that come after.

ESRI imagery although lower resolution is generally better aligned and better corrected for the hills than Bing, at least in northern Sweden. The government-provided Trafikverket NVDB overlay is quite reliable concerning alignment, although some minor short roads inside cities may have simplified geometry. I’d say that 90% of the case, NVDB alignment is good, and when it’s bad it’s usually less than 10 meters off. Thus NVDB overlay is good as a guide to align satellite imagery. Note that in hilly areas, you may need to realign the satellite imagery often even when moving just a few hundreds of meters.

For added aligment reference the Strava layer is a very good complement. Note that you need to be smart about what Strava shows, if you have a road with a cycle way on one side, most Strava users are probably cyclists that have been using the cycle way and not the road.

It’s common that old road geometry already in OSM has poor alignment, as much of the mapping was done before NVDB was public and satellite imagery alignment was even worse than today and Strava did not exist. So in some cases one may need to correct the road geometry first before one can add buildings.

If there is no NVDB geometry or Strava tracks nearby so you only can use satellite imagery, I suggest using ESRI rather than Bing. But there’s one more trick - the government-provided Lantmäteriet Historic 1960 imagery is corrected and aligned with modern standards, so if there are natural features or other features that haven’t changed in 60 years to align with, you can use the historic photo as reference.

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