[OSM-talk] OSM needs a measure for completeness
Martin Trautmann
traut at gmx.de
Mon Feb 4 07:30:48 GMT 2008
Chris Morley wrote:
> I have started a new thread with a measure for completeness in the title
> because this is an important topic for OSM. But the response to the
> recent posts quoted above, and my raising of it last July, has been only
> luke-warm.
I've added http://wiki.openstreetmap.org/index.php/Straßenschlüssel to
the wiki, a German description how to measure completeness:
Completeness may be verified most easily for roads.
Primary/secondary/.. are listed on most maps. The approach here is
focused more on residential:
1) various sources for lists of roads:
You may take names from city maps, get them from postal area codes, from
telephone books, from address collections and many other sources.
2) encoding of valuable stuff
There's a German system how an address may be encoded. It's based on the
abbreviations which are used for car plates, an official key for the
community, an official list of roads, the house number and the first
letters of one's name. This official list of roads assigns a five digit
number. This list does include especially all addresses where someone
lives. Thus minor tracks or not necessarily included: The finer details
differ from community to community. Roads outside the residential areas
are not part of these lists.
This encoding system is called "FEIN" or "EIN". It is recommended by the
police. The road lists (German: "Straßenschlüssel") are used for other
tasks as well (statistics, ownership, tax, maintenance, ...).
The German cycling club (ADFC) uses this system for bicycle encoding as
a matter of theft protection. That's why they offer a web service to
obtain the personal EIN code for anyone:
<http://fa-technik.adfc.de/code/ein>
3) opengeodb
On the ADFC site there's a another web interface for the opengeodb data
maintenance, which holds information about many places in Central Europe
<http://fa-technik.adfc.de/code/opengeodb.pl>. These combined datas, the
road lists and the opengeodb info, can be used to match OSM data and
highway tags. The result is a certain measure of completeness, how many
percent of those roads have been tagged by now. It does not include any
other stuff that is worth tagging (where it may be more difficult how to
measure completeness) and it does lack many tracks or details about the
quality of the data (lanes, speed limits, total length etc.)
Three larger federal states have been processed by now, see
http://wiki.openstreetmap.org/index.php/Category:Statistics
-> Baden-Württemberg
-> Nordrhein-Westfalen / North Rhine-Westphalia
-> Bayern / Bavaria
-> Oberbayern
-> Niederbayern
One result is a number in percent how many of those residential roads
have been tagged. As another result, a second phase may be applied to
identify incorrect spellings: see
http://wiki.openstreetmap.org/index.php/Talk:Baden-Württemberg#Korrekturvorschläge
(suggestions for fixes)
I guess that road lists are available almost everywhere. Does anyone
else do a match for larger regions, instead of the local area?
- Martin
More information about the talk
mailing list