[OSM-talk-be] Addresses in Belgium

[Sander Deryckere]

After the articles about  the addresses in Germany (where every average
German contributor should gather 1000 addresses), I wondered how we were
doing in Belgium. So I downloaded the address information in Belgium and
did some counting.

I only counted the addr:housenumber and addr:street tags. I didn't occupy
myself with the associatedstreet relations, as I've not that often seen
those on their own. If you think I'm wrong, I can do my counting again. I
also didn't take the addr:interpolation into account. Just because it's
difficult to analyse it.



The first thing you notice is that there are a lot of features with
housenumber information, but without street information. While other
information (such as city) can be determined from closed boundaries. It's
often ambiguous and hard to determine the street from other OSM features.

Some applications (s.a. Nominatim) implement the "street guessing",
sometimes with wrong results. Other apps (s.a. OsmAnd) just don't include
houses without street information in their search, so that info is
completely lost.

Now, how many addresses would be missing. We can't assume Belgium has 11
million addresses, as many people live together. So I searched other data.
The number of addresses in Belgium seems impossible to find, but I did find
the number of families in Belgium:
http://www.centrumvoorsociaalbeleid.be/indicatoren/index.php?q=node/176. I
assume that the number of addresses must be about the same. There are
addresses without families (like firms) and multiple families living in one
apartment with one address (but often different post boxes).

So that means we're needing about 4.5 million addresses and currently have
112 000. The completeness is thus about 2.5% of address data. Not a very
good number. When searching 40 addresses, only 1 on average will be found
in OSM.

But it becomes better when we look how the data evolved. Of that 112 000
addresses, there are 76 000 created (or modified) in 2012 and 105 000 since
2011. That means that the number of addresses created is going up  If we
can keep a bit of growth, we could map the majority of addresses in a few
years.

So continue with the effort, and map as many addresses as possible.

*How to map?*

There's also a lot of armchair mapping that can be done. First of all, all
that streetnames that need to be added. People are better in guessing the
right streetname, and if there's doubt, just add a fixme tag.

Next to that, if you see a restaurant on the map, without address data,
just search the website of that restaurant and get the address data from
there. You're doing nothing wrong, as long as you don't take the data from
a database (such as the golden pages), you aren't violating any copyrights
or database rights. While you're at the website of the restaurant, you can
also add other information s.a. opening hours or phone number.

Of course, when the weather is good, you can go out and map addresses. I
normally use photo mapping because it's so fast (and if you see an other
feature, you can also just take a picture of it), but there are also apps
for that, s.a. the Keypadmapper app for Android.

Regards,
Sander
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk-be/attachments/20121222/d7c3df7d/attachment.htm>