Perhaps of note: The definition of compacted calls it a mix of gravel and sand. Top image shows a surface where the material also contains quite an amount of even finer particles than sand. Some say, these are essential to make the material compactable. As far as I know, neither gravel nor sand can be compacted, in the sense that the term is used in construction.
Both are compacted. The difference is that Pic1 shows a super smooth perfect compaction whereas Pic2 shows a rough compaction only. There is loose gravel specially at the right side of the second track but the center is a compacted material mix although the quality of the work is a bit poor. To distinguih between the 2 tracks I would use smoothness.
In construction you would not even try to compact a track made up of sand or round gravel only. Crushed stone can be compacted to a certain extend but it would not last long when the fine grain sizes are missing. The better the mixture, the smoother the ride and the longer the track will last.
The linked definition doesnât call for a combination including âsandâ, it calls for a combination of coarser and finer aggregate, then compacted.
Compacting can be with a roller, or when used as a road or path, by tires or feet.
I interpret that picture as the compaction only done by the tyres of fat lorries that just happened to drive all a similar path :)
The linked description curiously requires compaction by a roller. In my area such ways almost always compacted by plates, so not compacted?
UPDATE: From looking at pic 2, Iâd say, there were truckloads of coarse gravel poured on the landscape and the heavy trucks driving there just pushed that into the existing ground that has the fine components to create the mix â so the selection in the poll might have to be expanded, surface=ground? But that is too late.
For sure not. You would not press gravel of that dimension into the ground which apparently is dry as a bone. Also you can see the material mix at the right side of that track which is not compacted. We called this stuff âbase courseâ and normally used it for the lower layer of a compacted or lateron asphalted road, but also for temporary tracks like the one in your pic.
Again the surface looks too consistent to be merely the result of heavy traffic passing there. But even if that would be the case it is still a compacted surface, not matter if compaction is done by rubber wheels, a rubber or steel roller or a vibration plate.
This is just those finer particles @Hungerburg mentioned working their magic. The materials and their ratios are selected so that they fit really tightly together, not too dissimilar to water-bound macadam, but theyâre not âgluedâ together like in concrete.
Ehee, and where is that documented? I could not find any description in the wiki documenting the difference between as properly compacted track and one which is compacted but not proper. As such I trust my professional experience which tells me this track is compacted, even if it is not as smooth as the perfect surface in sample 1.
Apparently, none of us is very familiar with the compacting technology. The linked Wikipedia entry shortly states that
Richard Edgeworth, who filled the gaps between the surface stones with a mixture of stone dust and water, providing a smoother surface for the increased traffic using the roads. This basic method of construction is sometimes known as water-bound macadam. Although this method required a great deal of manual labour, it resulted in a strong and free-draining pavement.
So, feel free to reword our Wiki accordingly. As everyone here well knows, âwikifiddlingâ wonât magically change how the tag has been used, and will have little influence how itâs going to be used in the future.
Personally, I use compacted for any smooth-surface gravel road that is apparently improved and maintained, such as in this YouTube video (itâs poor quality and in shade, so itâs hard to tell much about the surface, except that the car has no problem other than potholes). There arenât that many compacted in Serbia, and mostly those are unclassified ones where asphalting is not economic, due to low usage.
It is entirely possible it is not documented. Researching this properly would likely require asking mappers in way similar as done in this poll.
Sadly, documentation of even quite import tagging is quite lacking. I tried to do it a bit with for example surface= but it is quite time consuming to do it properly for widely used tags (as you should document actual usage, not how you would design tagging scheme).
And results will in part document confusion and divergences.
I can understand the logic of saying âdifferent sizes of material, pressed together somehow = compactedâ. But how does that line of thinking fit into the established OSM surface keys?
We can perhaps assume that any highway=* has had someone go over it, so 1/2 of the criteria for compacted is always true (i.e. compacted by feet or tires). Basically, unless itâs only uniformly sized gravel or sand or mud, every unpaved road would be surface=compacted?
Do you believe this is what the documentation says or intends to say? That this is what is presently being mapped in OSM? That this would be a good way to map, so youâre doing it no matter what others may think the keys mean?
If the answer to any of those questions is yes, Iâm a bit worried because there are (at least locally) initiatives to âat least map surfaceâ to highways that have no additional tags. Surface is thought to have some meaning and capability to usefully distinguish between roads, by at least some mappers. Smoothness was suggested in the other thread, but that tag seems to have even more interpretation issues than this one.
On a personal note, I would be quite angry if I encountered a 20km stretch of road like in the second picture tagged only as compacted, while travelling on a bicycle. And I have no motivation to tag information that isnât useful for mapping/routing, e.g. like this interpretation of compacted.
The discussion about tracktype, surface and smoothness is spinning around and around and around âŚ
When I classify a track I look at what is present on the ground. If it is a mix of gravel of different grain size where the top layer is not loose stuff which one can easily brush away by hand then it is compacted.
The difference between this surface and loose gravel can clearly be seen on the sample pic. On the right shoulder you see loose gravel, in the center there is a compacted gravel mix. It is not super smooth to be ridden by a race bike but you can easily travel that one with a mtb or gravel bike. To specify this we have the smoothness tag.
Quite some people chimed in and cast votes. I have not looked at the results yet. From what I learned: For me the second picture shows gravel. It is on the borders, it is in the very centre between where the tyres go. So the surface likely never seen a roller. Having looked closer at the image, there is some nice coarse crushed gravel there, two inch diameter pieces, ten centimetres thick at least. Perhaps some dirt thrown over that. Not enough in my opinion to make the whole of the surface compacted in the sense of the definition. At least not, when looking at what pictures presented in definition.
If I had a say in defining what OSM tags represent, I just hope this second picture will not make it into the definition, but rather that the phrasing of the definition should match closer the pictures shown there.
BTW: Such surfaces rare, from the looks of the photo, this is a service type highway not meant to last. Now going to vote. UPDATE: Results quite some surprise, certainly worth the wait!
I happen to quite often pass by unpaved ways, mostly of the track kind. Lots have a tracktype set, few have a surface set, nearly none a smoothness. I observed in the last two years, that the selection of applicable surfaces gradually diminished. Gravel is only for beds of two inch diameter crushed gravel, pebblestone is only for beds of loose one inch diameter pebbles, fine_gravel is only for beds of two inch deep 5mm gravel. These are of no use to map surfaces of thoroughfares. Maybe the documentation became more stringent, but mappers left with âunpavedâ?
