[Talk-gh] Unverifiable speed limits resulting from organised mapping in Accra
Stephen Mawutor Donkor
stevdok at gmail.com
Tue Nov 5 09:52:28 UTC 2024
For your reference
1 Ghana Driver’s Guide ** make reference to page 3.
https://mrh.gov.gh/wp-content/uploads/2022/09/Ghana-Drivers-Guide-_Final_Signed.pdf
2 Speed limits on Ghana roads
https://www.youtube.com/watch?v=7flkwDk2Buc
for all other references which were not accessible from my earlier email
see below.:
https://drive.google.com/file/d/181DZYKNOA-ispSR-tEqyRLFmizzKPLvp/view?usp=sharing
Regards
On Mon, Nov 4, 2024 at 6:33 PM Enock Seth Nyamador via Talk-gh <
talk-gh at openstreetmap.org> wrote:
> Hi Mawutor and TomTom,
>
> My comments are not meant to be in anyway harsh towards any person or
> group of persons. Unfortunately, I only tell about the reality of the
> results of such mapping campaigns which tend reside in OSM for who knows
> how long. It is ok to know that some communication have been done with
> the community in Ghana but where is this publicly? Any OSM wiki page or
> discussions? I am afraid to say if some regulation say roads in urban
> areas are eg. 30 km/h doesn't mean we should assume and map all roads
> with 30 km/h, even if there are no existing street signs or on roads
> that lead nowhere. How do other mappers verify these contributions?
>
> I must say issues need not arise always, most of them can be easily and
> should be avoided. We can make OpenStreetMap better if these kinds of
> mapping are discussed in the wider community, well documented, avoided
> or corrected in their early stages.
>
> Unfortunately, the references you shared are not accessible.
>
> Best,
> Enock
>
> On 04.11.24 17:38, Stephen Mawutor Donkor wrote:
> >
> > Thank you, Enock, for sharing the reference links; they will be
> > valuable in expanding on the ongoing investigation of the speed limit
> > data collection conducted in Accra by the TomTom Team.
> >
> > I'd like to add that the TomTom Team didn't carry out this project
> > independently; they engaged closely with our community. The project
> > involved selected members of the YouthMappers community in Ghana,
> > though participation was limited to fewer than 20 trained individuals
> > who contributed to the mapping, for your information this campaign was
> > excluded of newbies; as you mentioned other wise. one needed to be an
> > intermediate or advance mapper to join the team.
> >
> > Some issues have already been flagged, and Tomtom is/are exploring
> > ways to addressing them.
> >
> > We’ve noticed instances where some participants didn’t refer to
> > Mapillary road sign data from our closing conversations, and in other
> > cases, certain speed limits recorded did not align with the reference
> > standards we were using.
> >
> > While I feel that some feedback has been a bit harsh, I also believe
> > we are all here to learn from others and our own experiences. When
> > mistakes happen, it’s essential to focus on constructive solutions and
> > use them as learning curves/opportunities for all, not just be.
> >
> > Make ref to:
> >
> > [Ref_1] where some of the mappers shared ground truff data just to
> > validate their data
> >
> > [Ref_4]the mappers were taught how to use mappillary data. sadly the
> > data doesn't cover much. We want as much as conducting a mappillary
> > campaign but you guess it is as good as mine.
> >
> > [Ref_2] some strange speed limits on highways
> >
> > [Ref_3] when mappers were unsure about what to do brough the
> > conversation back to the group.
> >
> > once again, thank you for your continuous interest in the quality of
> > data coming Ghana and in the OSM ecosystem, I would like to encourage
> > you to continually share your constructive feedback for the betterment
> > of the community and solutions to make some of these processes smoother.
> >
> > thank you
> > Mawutor
> >
> >
> > ref_4:
> >
> https://drive.google.com/file/d/1Hmn7BiQnNuj-bagFPmOogFEJFsUTO6eF/view?usp=drive_link
> >
> > ref_3:
> >
> https://drive.google.com/file/d/14YRssyg1a7NOxAh6G4iSKqetdxTRRkpj/view?usp=drive_link
> >
> > ref_2:
> >
> https://drive.google.com/file/d/1y5Qd-KbhR4a6UXHa0SryyC8uZCN2yDOz/view?usp=drive_link
> >
> > ref_1:
> >
> https://drive.google.com/file/d/1UOQXSjyBvD0ee8Mkmum4yL2TNQ9rdU6o/view?usp=drive_link
> >
> >
> > On Mon, Nov 4, 2024 at 12:31 PM Enock Seth Nyamador via Talk-gh
> > <talk-gh at openstreetmap.org> wrote:
> >
> > Dear Hajar and TomTom (mappers),
> >
> > In reference to my comments on your maxspeed=* mapping in Accra [1].
> > There are multiple frightening maxspeed=* from this mapping which are
> > completely unverifiable. I also see roads which of course lead
> > nowhere
> > and were results of other organised mapping campaigns tagged with
> > maxspeed=* without any further investigation.
> >
> > I would have expected that this kind of organised mapping is
> > discussed
> > publicly and documented on the OSM Wiki. As of 2024-08-23, there is
> > only one road in Accra on OSM with verifiable speed limit of 100 km/h
> > [2]. Seeing roads in dense Accra Central even with existing adjacent
> > verifiable maxspeed=50 tagged with higher maxspeed=90/100 [3][3a]
> > makes
> > me wonder. I have also seen lower maxspeed values where there
> > exist some
> > street-level images to validate eg. way [4] (maxspeed=30) and
> > Mapillary
> > image [5] (street sign 50).
> >
> > TomTom's mapping team I believe is better aware and in the
> > position to
> > post-process all roads wherever and add whatever desired speed, see
> > Default speed limits [6], but outsourcing to a bunch of newbies to
> > add
> > into OSM, is not what OpenStreetMap is about.
> >
> > As I have always commented on this list and elsewhere there is
> > just too
> > much useless data from many undocumented organised mapping
> > activities in
> > Ghana that needs to be deleted in the end, hence we don't want to see
> > new problems that will never be fixed.
> >
> > The practice of setting up a series of maproulette or HOTOSM Tasking
> > manager instance projects and letting it fix itself is not helping
> > but
> > continues take place from multiple actors in Ghana and elsewhere.
> >
> > Please kindly find the best way to undo all maxspeed=* resulting from
> > this organised mapping campaign without damaging existing valid ones
> > e.g. manually, contact DWG, etc.
> >
> > 1. https://maproulette.org/browse/challenges/48926
> > 2. https://overpass-turbo.eu/s/1TCn
> > 3.
> >
> https://www.openstreetbrowser.org/#map=17/5.54911/-0.20774&basemap=osm-mapnik&categories=car_maxspeed
> > 3a
> > <
> https://www.openstreetbrowser.org/#map=17/5.54911/-0.20774&basemap=osm-mapnik&categories=car_maxspeed3a
> >.
> > https://overpass-turbo.eu/s/1TCC
> > 4. https://www.openstreetmap.org/way/169135203/history/7
> > 5.
> >
> https://www.mapillary.com/app/?lat=5.551382553813923&lng=-0.19400795959847983&z=19.9&pKey=517473239420891&focus=photo
> > <
> https://www.mapillary.com/app/?lat=5.551382553813923&lng=-0.19400795959847983&z=19.9&pKey=517473239420891&focus=photo
> >
> > 6. https://wiki.openstreetmap.org/wiki/Default_speed_limits
> >
> > Best,
> > Enock
> >
> >
> > _______________________________________________
> > Talk-gh mailing list
> > Talk-gh at openstreetmap.org
> > https://lists.openstreetmap.org/listinfo/talk-gh
> >
> >
> >
> > --
> > Stephen Mawutor Donkor
> > M: +233 (020) 8254044
> > T: @stevdok
> > S: stevdok
> >
> >
> > /"Mere philosophy will not satisfy us.We cannot reach the goal by mere
> > words alone.Without practice, nothing can be achieved" - Sri S.
> > Satchidananda/
>
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>
--
Stephen Mawutor Donkor
M: +233 (020) 8254044
T: @stevdok
S: stevdok
*"Mere philosophy will not satisfy us.We cannot reach the goal by mere
words alone.Without practice, nothing can be achieved" - Sri S.
Satchidananda*
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