Redirecting GrabOSM here to discuss mapping updates and how to prevent further issues relating to their new campaign:
I have informed Grab a few months ago to contact us through the forum and review the note companies that @stephankn has added at the top of the Thailand wiki page:
Grab stopped mapping for a few months, didn’t respond to my request, but started this week a new campaign, so I have asked them to join the discussion here asap before doing any further damage.
Like Facebook in the past, Grab recent mapping campaigns brought a lot of frustrations among the local mapper community, I have personally literally spent dozens if not hundreds of hours fixing minor road classifications, exaggerated curves… but only managed to correct small geographical areas.
First, it’s important to know that most Grab mappers are sitting in India (Bangalore) and doing changes only with imagery in neighboring countries for which they have no local knowledge.
Past issues have been:
- conflicting minor road classification: even after we improved the wiki to address this issue, I learned directly from Grab mappers that they were asked to continue tagging any road with visible rooftops as residential…
- no consistency or internal quality check: I found mappers tagging the exact same type of road as service, unclassified, or residential even next to each other.
- overriding existing classifications: without local knowledge Grab mappers literally went through existing correctly tagged service roads (universities, gov facilities, parks) and changed them to residential (because of rooftops)…
- taking control of maps: at some point, Grab mappers were assigned areas to watch and were literally reverting local mappers changes (e.g. reverting their classification) within hours
- long roads with unnecessary and exaggerated curves: in areas with little coverage, Grab mappers are connecting highways to houses with a single road segment even if the way involved 5 different roads intersection with hard turns and a private driveway. The worst part: the road will be curved at straight intersections with dozens of nodes, so you end up with a curved zig zag that will need to eventually split into multiple segments, the curves make it too much work to fix so I usually delete these when I find them.
In this new Grab campaign, I see so far mostly minor changes like adding dead-end (noexit=yes) or fixing not properly connected road segments for routing and I really hope these are based on feedback from local knowledge (e.g. Grab drivers).
My main requests for GrabOSM to prevent further damage would be to:
- tag new roads based strictly on the Thailand wiki minor road classification
- NOT change any classification to existing roads without local knowledge (leave this to local mappers)
- quality control your mappers’ changes
- combine mappers changes in fewer changesets so it’s easier to review and revert in case of conflicts
- stop curving roads at visible straight intersections
@ Other local mappers: especially those who had to deal with Facebook campaigns, please kindly give your suggestions or advice on how to move forward.
@ GRABOSM: have any of these previous issues been addressed internally and what is your goal for your next campaign(s) ?