Milhouse,

My issue with this discussion is calling such changes "incorrect" or "bad mapping" when objectively they are not. I do not see why amalash would need to acknowledge that. Incomplete data are a norm - just look at this map, there are partially mapped fences or individual trees - someone found them useful or simply had fun mapping them.

I don't have an opinion on the sidewalk= tag but having data duplicated at at different levels of detail should be fine, maybe even useful.

BTW, I see at least one reason _not_ to use sidewalk= tags (but I would never discourage them!). When the pavement is discontinuous it chops the road way into multiple segments. This can become unwieldy when combined with other similar tags (speed limits, surface, lane count, dropped kerbs, bus lines).