stevea (2018-09-30 18:38:29+00:00): Gleb, there are two imports we are talking about here.  One was OSM-US' TIGER import of roads and rail in 2007-8, which many agree was of poor quality, but we are more-or-less "stuck" with it, and the solution is to improve it with better-and-better developing strategies.  Some people estimate it might take thirty years to clean up TIGER in the USA.  OK, maybe it will.

The other import was the SCCGIS landuse import that nmixter (a friend of mine who I and many others have reviled and even ridiculed at his poor and wide-ranging imports all over California).  If you read our County wiki page, you'll see HE "made the mess of the initial import" and I am the one (with some others) who has spent many years, thousands of edits and countless hours improving these data to a state of "decency."  (You have every right to disagree with that word).  I have also said that when the present v3 discovers that SCCGIS offers newer data (2020? 2021?) and might become v4, I endeavor to enter the data with shared multipolygon boundaries where/as it makes sense to do so.  This is highly ambitious, shows my continuing dedication to improving the map in ways that it naturally evolves, keeps me and others engaged in how best to improve our County data and opens the gigantic discussion of the difficulties about how best to conflate.

When you say "the exported data are of very bad quality" I don't know if you are talking about TIGER, SCCGIS or both.  I think "both."  I agree that TIGER's rural roads in the mountains are atrocious, closer to "an hallucination" rather than reality.  Please, as you know better reality, fix these.  I believe you are doing fine so far; I and the map greatly appreciate your good, solid work.

I, too, would like others to join this discussion.  I, too, would like OSM to become "the best damn map in the world."  I was NOT the person who imported TIGER, nor did I import the SCCGIS data, rather, I painstakingly improved the SCCGIS data from the hideous mess that arose from nmixter's "trigger happy import finger" as best I could, and this untangling took years of my best efforts.  People like you who seem "closer to the action" (you live here, too, as you say) DO improve the map, and rightly so; I am very glad of that.  It isn't that you and/or others are being asked to be "hands off" the imported data, I and others WANT you and others to improve the imported data, and you are.  (You complain about it, I hear you loud and clear).  What we asked you to be "hands off" about was the "reltoolbox" automation of polygon edge conflation that you were doing, which made bad data that were getting better MUCH more confusing, especially for novice editors (and we need all the new mappers we can get).

I agree with you that decades-old data like TIGER and SCCGIS imports were an early "first draft" to get SOME data into the map so it wasn't such a blank canvas.  We are beyond doing such things today in areas as richly data-populated as our County (though I'd honestly call it "medium data populated" rather than "richly").  There are no new imports proposed — except the possible improvements a v4 SCCGIS landuse import MIGHT offer; we haven't had that discussion yet as newer data won't be available for a couple/few years.  Simultaneously, we can and should improve these data, with, yes, I agree with you 100%, "truth on the ground" approach.  Even our wiki says that the landuse import (again, not my idea, not my doing, though my passion to clean up, yes) was "a first step to getting some landuse data into the map" and that more details and better data would follow.  That is exactly what you are doing, and correctly so.

Regarding "A wood where in reality there is a meadow - multiple examples. Vice versa - multiple examples."  Here is my (partial) answer:  there continues to be misunderstanding/debate about landuse vs. landcover.  The SCCGIS data did tag as landuse=forest areas which were imported as TP (Timber Production, that is clearly "forest" as OSM means it).  Sometimes, a clearing (meadow) could be seen upon this land (trees were felled in a timber forest, nothing strange about that) and so we would superimpose a landuse=meadow on top of that.  Amazingly, mapnik/Standard (now Carto) rendered that quite pleasingly.  Likewise, many areas which the County zones (remember, zoning is only a "first step" at accurate landuse mapping, and landcover is not landuse) as "farmland" may largely be covered with trees.  Many of these areas are orchards, vineyards or simply "still trees" but the land COULD be used for agricultural cultivation, which technically makes the "landuse=farmland" 100% accurate, even as a visual/aerial/satellite/on-the-ground observation might say "hey, there's nothing but TREES here, why is this tagged FARMland?!"  Because that's what its landuse actually is, that's why.  Let's not (between simply the two of us) debate landuse vs. landcover, we are not going to solve it without the help of the much larger OSM community.

I suggest we take this to the Discussion page of Santa Cruz County's wiki:  https://wiki.osm.org/wiki/Talk:Santa_Cruz_County,_California .  That page hasn't been touched in 8-1/2 years and it is time to take it there so it is more public than in a Changeset Comment like here.

Honestly, I believe our goals are much more inline with each other than they are at odds with each other.  We have some "chunks of junk" that need improvement/clean-up (just like TIGER, but simultaneously with much grumbling/complaining but also some good strategies — and we are cleaning that up, too).  You are doing good work at cleaning up the imported data around here (both TIGER roads and SCCGIS landuse polygons).  Yes, it is slow going, it will take years.  (It took me about five years to clean up Nathan/nmixter's SCCGIS v1 data through v2 cleanup and v3 re-import).  The map is a big place, the world is a big place.  Our county is a finite amount of data in OSM.  It is a substantial amount of data, but it isn't so large that a project like ours, with cooperation and consensus among its participants (like us) can't get it done — we CAN get it done and we ARE getting it done.

Best regards,
Steve