[Imports] NYC building + address import - to merge or not to merge?

Johan C osmned at gmail.com
Thu Oct 17 16:45:11 UTC 2013


> Well, as noted above, we won't be consistent, with manual mapping being
> done both ways.

That's correct from the stats. And from the wiki, which shows it's okay to
add addresses to the elements nodes and areas
http://wiki.openstreetmap.org/wiki/Key:addr:housenumber
http://wiki.openstreetmap.org/wiki/Addresses

This means the decision process 'to merge or not to merge' can be exercised
by the local community.

Cheers, Johan

ps I am however quite interested in the considerations the NYC community
uses for this decision, please share them

2013/10/17 Paul Norman <penorman at mac.com>

> I've been sitting on this message, running some stats, but here it is
>
> > From: Alex Barth [mailto:alex at mapbox.com]
> > Sent: Monday, October 14, 2013 9:35 AM
> > To: Imports OpenStreetMap.org
> > Subject: [Imports] NYC building + address import - to merge or not to
> merge?
> >
> > Now there's reason to revisit this decision: the data steward (Colin
> > Reilly from NYC GIS) told me that NYC GIS took great care to place
> > addresses at about where the entrance of the building sits.
>
> A review of the data shows that this may be true for some buildings and
> addresses but is not true for others. As an example, see
>
> http://pnorman.dev.openstreetmap.org/imports/review/ny_buildings/positions.png
> .
> Some points are near addresses, some are near centroids, and some of
> them are strangely at the back.
>
> > Here is a comparison of the two options. I'd like to discuss and
> > decide at tonight's imports hangout.
>
> Note: Alex, Serge and myself discussed the import at length tonight.
>
> > ## Option 1: Merge addresses into buildings where possible
> >
> > ## Option 2: Always keep address points separate
>
> There is some repetition in the two sections, so I'm just going to extract
> and rearrange points. See
> http://lists.osm.org/pipermail/imports/2013-October/002275.html for the
> original text
>
> > a) [points] is the NYC GIS way, making it nicer for GIS folks to use OSM
>
> GIS folks will have to deal with both so this doesn't really give either
> method an advantage. There *will* be addresses on ways that they will
> have to deal with. Additionally NYC is only part of OSM, so they have to
> deal with practices elsewhere anyways.
>
> > a) we lose data [when merging points to buildings]
>
> I'd say the information lost is not significant, given that in many
> buildings the point is just the centroid or a random point within the
> building. It's not consistent enough to rely on for anything, as you've
> stated:
>
> > Note: it has been suggested to use the address location information to
> > tag an entrance. Unfortunately the data is not consistent enough to do
> > this.
>
> > b) Not regarding standing practice, merging addresses into buildings
> > is an exception from the generally applicable method of doing separate
> > address points.
> > b) [merging] makes it harder for NYC GIS to leverage OSM
>
> How so? Keep in mind that NYC GIS will have to deal with
>
> - Addresses collected manually without any import tags
>
> - Addresses on building ways
>
> - Addresses on building ways where neither the address or building way
>   comes from an import
>
> - Addresses on building ways where OSM has split up a structure
>   differently than they have
>
> For consumers other than NYC GIS, they'll be in the same position of
> multiple styles of mapping.
>
> > a) [Addresses on nodes inside buildings] diverges (but does not
>   violate) common OSM practice
> > a) [Addresses on ways] is how a lot of buildings are done in OSM
>
> Unfortunately statistics are distorted by imports, but I had a look at
> similar practices with merging and POIs with name=McDonald's.
>
> Of the 5523 locations which could be merged to building polygons, 3315, or
> 60% were. There were another 5205 locations which were unable to be merged
> onto a building, either because there were multiple POIs within the
> building, or there was no building mapped. The actual percentage may be
> higher as this I can imagine scenarios where the mapper knew there was
> another POI in the building but it wasn't mapped.
>
> Results for 80% for name=Walmart and 60% for name=Safeway.
>
> > Note right now we've imported data in both formats :p I'm not worried
> > about this and I'll commit to make sure in the end we're consistent.
>
> Well, as noted above, we won't be consistent, with manual mapping being
> done both ways.
>
>
> _______________________________________________
> Imports mailing list
> Imports at openstreetmap.org
> https://lists.openstreetmap.org/listinfo/imports
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/imports/attachments/20131017/903295a0/attachment.html>


More information about the Imports mailing list