I want to say something to this, too. I´m using JOSM and as described by 
Ævar before the import, this was a easy to check all the data with the 
help of the color set. Thanks go to the authors.

I spent the last two days cleaning up Easticeland and parts of the 
eastern mid-highland. OK, these were two hard days but at least there is 
quite a lot new data now. A lot of ways that no one was driving before. 
Check the ways in the 900 area (besides that, am I the only one adding 
and caring the road system website on Icelandic wikipedia?!)

There is in fact a lot of useful information in the data itself. And the 
connecting of all the ways and reconnecting is a quite big amount of 
work, but I´m sure you get through this.

Anyways after spending some 35 hours the last two days I can tell one: I 
deleted around 90% of the data because it was already on OSM (shows the 
progress in OSM and the quality of the OSM data is IMHO in 95% of the 
ways I checked far superior), 10% is a good deal so far. And talking 
about the "5%". But there were a lot of highland tracks with great 
accuracy in the OFP data. I think this is not a perfect solution but all 
these roads that possibly might be taken from a map I marked with a 
FIXME for resurvey. Especially roads that are just 5 points on 10km seem 
quite suspicious to me. But anyways, who knows, maybe they are just very 
simplified? OSM is a dynamic project that will never end or be finished, 
so we always have the chance to kill hese resurvey ways. And for 95% of 
the ways I added there is still the source=ourfootprints tag to find the 
ways.

And while checking the data I added and corrected some OSM data and 
relations as well.

Thank you again to Ævar for the import.

Greetings from the far east to the south...

Christoph


Am 17.01.2010 21:27, schrieb Ævar Arnfjörð Bjarmason:
> On Sun, Jan 17, 2010 at 20:29, Karl Palsson<[email protected]>  wrote:
>> Ævar Arnfjörð Bjarmason wrote:
>>> Tom að mestu rakið vegi bæði frá egin GPS ferlum og u.þ.b. 30 annara
>>> sem hafa sent honum gögn en hann segir að um 95% af kortinu sé búið
>>> til svona, 5% er teiknað eftir lokuðum kortum (LMÍ kortum geri ég ráð
>>> fyrir), ár, vötn, jöklar og strandlengjan eru svo teiknuð eftir Google
>>> Satellite myndum.
>>
>> How did you go about excluding the 5% that were copied from other maps?  You 
>> do
>> know that importing this has totally corrupted any claim OSM might have on 
>> being
>> completely clean data?
>
> 5% of Tom's source dataset is partially derived from Google Maps / LMÍ
> but none of what just got imported on OpenStreetMap.
>
> What the ourFootPrints import imported was a subset of the
> ourfootprints.de dataset, it was just the GPX traced ways&  none of
> the Google Satellite traced waterways, POIs or various other things
> that were either unfit for importing or we'll possibly do in the
> future.
>
>> Further, what possibly motivated you to import this over reykjavik?  We now 
>> have
>> a great big pile of vomit, with no real known source or age, whose only real
>> qualification is that a bunch of Germans made it before OSM existed.  Good 
>> for
>> them.
>
> When you do any sort of data import into an area with existing data
> you're going to have conflicts. There are a few ways to deal with
> that:
>
>    * Delete all the existing data&  Import the new one, obviously not
> applicable here but this was done e.g. in Gaza
>    * Try to automatically or manually detect conflicts before
> uploading. This was done for the Corine import&  requires a lot of
> programming / debugging / testing work or manual labour by a limited
> group beforehand.
>    * Import the data on top of the existing data&  clean it up later
>
> I went with the last option after it became clear that most of the
> users doing regular edits (who replied on the list) were willing to
> help clean it up afterwards. The whole import is only around 8000 ways
> which isn't too big for such manual cleanup work.
>
> I'm sorry for any inconvenience this has caused and in the areas such
> as Reykjavík where this import affects most users (especially those
> using Potlatch such as yourself) I'll try to cleanup the data very
> soon. I probably would have done so already for the capital area
> except I've been fixing up the import slightly by deleting source=*
> tags on all the nodes I imported.
>
> Most of the OFP data in Reykjavík and its surroundings will be
> deleted, except some residential ways which haven't yet been covered
> by us (like some in Kópavogur) and a few tracks.
>
>> While this surely has some very positive outcomes in unmapped areas, in other
>> areas we now just have a mess that someone has to go out and _resurvey_ just 
>> to
>> try and work out which one is right.
>
> How is this a bad thing? Once we're done with the cleanup we'll have
> data in areas where we had none before. Sure that data may be out of
> date or incomplete but it's still *some* data instead of none at all.
>
> We may need to treat ourfootprints data as implicitly needing
> confirmation or resurveying of course, but in the meantime we at least
> have something.
>
>> Further, large chunks of the OFP import in reykjavik isn't even 
>> _semantically_
>> correct, let alone geographically correct.  Roads that overlay, but don't
>> intersect, Roads drawn as straight lines, which may have been straight on
>> original city plans, but clearly are not when you stand on the street, roads 
>> or
>> connections that don't exist anymore.
>
> Yes a lot of the OFP roads don't connect with each other (although
> some do). Errors like that can be easily fixed with the validator when
> the data is imported.
>
> As for the accuracy see the point above.
>
>> In some other parts of the country, this was _possibly_ a good idea, but I'm
>> sorry, I really think this was a bad idea to import the whole lot.
>
> Out in the country it was definitely a good idea. The import greatly
> expands our coverage of the national highway system&  various offroad
> tracks. The quality of those ways is on par with or even surpassing
> our own existing ways.
>
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