[Imports] Tanzania roads manual import

Rafael Avila Coya ravilacoya at gmail.com
Mon Aug 17 22:16:21 UTC 2015

Hi, Chistoph:

Thank you very much for your input. My comments inline:

On 14/08/15 21:17, Christoph Hormann wrote:
> On Thursday 13 August 2015, Rafael Avila Coya wrote:
>> An import wiki has been produced [3] and a detailed workflow with
>> lots of screenshots is being finished [4], with the goal of keeping
>> the highest consistency among users.
> In general this looks fine but there are a few issues:
> - without seeing the data it is not possible to judge the quality and 
> suitability for import.

As the license gives permission only for the import to OSM (before Sept.
2016), we can't put it freely available (in a Dropbox link for example),
as anyone accessing it must accept the license before downloading.

Please, just send an email to me or Andrew Inglis and we will send you
back a sample file of the whole data, so you can check it yourself (we
can consider that doing so you accept of the license).

> - if you advise the mappers to always run line simplifications on the 
> ways first it would be better to do this on the whole data set in 
> advance, this would avoid unnecessary work for the mappers.

Running the Simplify Way plugin for each task takes just seconds, when
each task can take an average of one hour. It's true that running the
Simplify way for the whole data would avoid this step for mappers, and I
obviously thought about it, but it seemed to freeze my JOSM when
applying the plugin to too many segments at the same time. I will check
if I can find a command line script that applies the algorithm and that
it works fine for all segments altogether.

> - Since other sources are necessary to decide on correct tagging the 
> question is what you intend to do in areas where no high resolution 
> images are available (which is the case in quite a few parts of 
> Tanzania) or where clouds or vegetation make a proper assessment 
> impossible.  There should be a clear plan what to do in those cases.

The workflow is still unfinished, and I will add instructions when no
Bing nor Mapbox are present. In those cases, when no OSM ways are
present, we can safely import the MSD&JSI segments as they are, bearing
in mind that they have been collected with GPS devices and, as you will
see, they are most of the time of very good quality. In case there are
OSM ways present, if both OSM and MSD&JSI look similar quality (similar
shape), or when just unsure, we should keep the OSM way.

> - Since the specific road paving material can usually not be determined 
> from satellite images the advise for tagging paved roads should be 
> surface=paved and not surface=asphalt.

Sometimes the imagery let's see clearly that surface=asphalt. But I
agree that in case of doubt we should stick to that paved/unpaved tagging.

> - Instead of 'source:date=2014..2015' use 'source:date=2014;2015'

I disagree. "2014..2015" means that the data has been collected any time
during 2014 and 2015. "2014;2015" means that the source dates are 2014
and 2015, and this is even incorrect itself, as each segment has been
collected one day of 2014 OR 2015, but not both in 2014 and 2015 at the
same time.

> - The 'license document' linked to does not really give permission to 
> use the data in OSM, it just says it will be made available through OSM 
> but no word about license and permission to use.  Even more the 
> agreement is limited until September 2016.

Andrew Inglis from JSI has already answered you about the license, so I
won't add anything to it.



Twitter: @ravilacoya <http://twitter.com/ravilacoya>
*Humanitarian OpenStreetMap Team (HOT)* <http://www.hotosm.org>

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