I would like to request a small “Roads geometry” guidelines section in the Thailand wiki to prevent any further basic editing issues like:
- roads with exaggerated curves (not parallel to straight lines)
- roads curved at visible intersections (where sharp corners are present)
- roads not split when branching out from the main way
- roads not split when there is a clear change of surface or highway classification
These surprisingly basic issues have become recently a pain point with GRABOSM daily mass addition of minor roads, making further corrections/extensions very frustrating.
Note: simply navigate to any rural area outside major Thai cities to see examples (e.g Chiang Mai, Chiang Rai…)
My proposal would be to refer them to a small section in the Thailand wiki that describes basic guidelines on how to create/modify road geometries.
This could be also very useful for new mappers.
Below are sample decision trees from my own personal guidelines, please feel to adapt to a different format/content:
## Splitting Road Segments: - does the road segment both follow the main way and branch out of it? - yes: split it at the junction and tag both segments separately - no: is there a major change of surface along the road segment? (from/to paved/unpaved, long sections) - yes: split it where the change occurs and tag both segments separately - no: does the road qualify for different highway classifications? - yes: is the main road purpose through traffic? - yes: do no split - no: split it where the change occurs and tag both segments separately - no: split it where the change occurs and tag both segments separately > Important: Do NOT curve road segments at visible intersections or exaggerate curves in other scenarios. ## Merging Road Segments: - are both road segments consecutive, follow the main way and share identical tag classification including surface, highway? - yes: both segments can be merged - no: do not merge