I generally agree, and sometimes i will delete a bad PGS feature to re-make it, but sometimes it's just as convenient to align it with JOSM's "improve way accuracy" tool.

Thank you very much! This greatly reduces the amount of work I have to in cleaning up OSM. I have done ~50 million nodes of import cleanup over 7 years, mostly NHD/Canvec in USA/Canada. It Vietnam could avoid excess in the first place, it will be very good.

Hi, I am unsure how you can avoid excessive nodes, because I don't know the process you are using to import. If the source you are importing from has this incredibly high node count, then you should run a "simplify" on the data before you upload it to OSM. If the source data is imagery, then it is inappropriate to derive data with higher precision than the source imagery. For example, if the maxar imagery being used has a resolution of 30cm, then the road data should not have node precision less than 30cm. Precision and accuracy are different things!

Hi Riyadi. Concerning the "source" tag on features, it is on the way to being deprecated; at the very least, it does not belong on new features. The source description belongs on the changeset, not every single feature that the changeset touches. In an environment such as OSM, there are a very large number of editors, and very few will respect or update the "source" tag on every element they touch; very quickly, the tag becomes inaccurate. I am not certain what you mean by "our" roads, but the roads of every country are the joint responsibility of all OSM editors, not any single group. If you want to do a search for which roads you have "input", the source tag is not the way to achieve that.

Hi Haris. While I appreciate your desire to "beautify" these roads, you are using far too many nodes. A road should have enough nodes to clearly define its location, no more. A good rule of thumb is to try reducing the line to a 20cm threshold; if nodes are removed, then they were excessive. Excessive nodes not only bloat the planet file, they also make the road much more difficult to maintain, because so many more nodes must be moved when the road is correctly. I will now have to clean up these excessive nodes you have made. At a quick glance, there are around 10,000 nodes that must be deleted in this (Thanh Chuong) are alone. Please stop!

Thanks, TheConductor. I defer to your local knowledge, although I did notice that the streambed in many places appears exceedingly narrow, so that even when water flows, it would not meet OSM's definition of a river, for those sections. In any case, I am just very happy that this river feature has someone looking out for it.

Actually the source was mostly Maxar, as it seems to be more recent than Bing here

Looking at the aerial, I agree. I have changed that section of the "purgatory trail" to be highway=unclassified, surface=unpaved

dpp, you introduced some major errors in this changeset. For example, you changed "ele=1181' MSL" to "ele=1181". The original is in feet (that's what the ' means) and by removing it, you have changed it to meters, without doing the feet-meters conversion.

In the future, be very careful about pressing 'Q' by accident, and please review your changes carefully before uploading!

Ricky, it appears that in this changeset, you selected a political boundary and accidentally "squared" it ("orthogonalize shape") which completely messed up the geometry. I would attempt to undo your changeset, but it seems you touched 607 ways and 4138 nodes, so you changed a lot beside this boundary way. I will attempt to revert just this way, to fix the damage.

Alifatri, I don't know why you did this, adding hundreds of inefficient, colinear "garbage" nodes to this way, but PLEASE stop. Perhaps you are using the FastDraw plugin and need to learn how to use its simplify feature? I hope you did not click a mouse 1210 times to make this way? You used 1210 nodes to draw a way which is perfectly modeled, with even more precision than the imagery, with less than 400 nodes.

Bonya, there are major issues with these streams:
1. You are using 4x too many nodes! Run simplifly before uploading, so we don't have to do it for you.
2. You used the wrong tag: these are clearly stream, not river.
3. Most of the stream directions are obviously wrong (uphill).

I am trying to fix it all, but please stop making so much cleanup work for us to do.

These are not tertiary roads! Only a substantially improved, wide road that leads to a significant settlement is a tertiary. Otherwise it is unclassified, or residential, or track. Please fix the 17000 "tertiary" roads you have created in Myanmar. If you need help, let us know.

Maximus, the ways in this upload are badly overnoded, e.g. streams with 480 nodes which are fully represented with only 180 nodes. It saves the OSM database a lot of inefficient churn if you trim out the noise _before_ you upload; otherwise, we just have to come along afterwards and delete it. Let me know if you need any help on how to do this.

Actually, this is NHD in Minnesota, just across the border (and sharing an edge with) the Canvec in Ontario, hence the mixup.

Hi Ikiya. I'm glad to hear that local mappers are paying attention! That is very good.

I can further explain the edits here in English, and you can forward them to the talk-ja mailing list? I do this kind of standard OSM cleanup for dozens of countries around the world and there is nothing Japan-specific about them.

For example: "Shikoku, tidy coastline to 60cm". In this case, a mapping account named "Laharl" did a raw import of coastline data, with source given as "GSI/KIBAN Block". However, this import was badly overnoded in some places, with hundreds of redundant and colinear nodes on small lengths of simple coastline. To fix the problem, in JOSM one can set the advanced property simplify-way.max-error to a very small value like 0.6 (60 cm). This removes the noise and redundancy, without moving the coastline at all cartographically.

The political boundaries are similar; they are legal entities which are not actually sub-meter precise, so the sub-meter node bloat is due entirely to GIS processing artifacts. These are easily removed with a simplify-way:max-error of a meter, although I used only 80cm in this case to be even more gentle and minimal change.

Please see these diary posts for more information, about Japan (@bdiscoe/diary/43428) and the general problem of overnoding (@bdiscoe/diary/37421 and @bdiscoe/diary/37473)

Omino, since you haven't responded in a while, i went ahead and changed your "dam" features to reflect what is actually present in relatively recent imagery (DigitalGlobe Premium is more recent than Bing, here)

Omino, could you explain what this is? You added a "water control area" and "gogo dam" water area, but this is downstream from where the actual and expanding gogo dam is. No changes appear here, even in very recent imagery. You may want to update or delete these non-existent "water" features?

dougcb68, these changesets contains intensely overnoded ways, at least 3x more nodes than are appropriate for rough natural features like natural waterways and coastlines. Please use "simplify" on your ways before uploaded to save a lot of work for people to come along afterward to delete your nodes! Feel free to ask if you need help knowing how to do this.