Talk:Tag:surface=compacted

I think the high quality with scooter photo is a better match to fine_gravel Tonyf1 (talk) 19:45, 24 November 2022 (UTC)

The documentation for fine_gravel says to the opposite, that tag should only be used where bicycle tyres sink in. Rest assured, I bet that consumers (e.g. bikerouter) will for long into the future treat fine_gravel as you think what it stands for, even though ambiguous, because that is what it has been used for by the mapping community in vast numbers, at least when found on tracks or cycleways. Hungerburg (talk) 18:51, 6 April 2026 (UTC)

Regional meaning of “gravel”

The statement that such roads are “also called gravel in many parts of the world” seems too broad. This may apply in some regions (e.g. Australia, New Zealand, parts of North America), where “gravel road” can refer to compacted aggregate, but not universally. Should this be clarified or qualified with regional context? --julcnx (talk) 13:56, 2 April 2026 (UTC)

Suggested fix: replace "some parts of the world" with "some parts of the world, notably Australia, New Zealand, and parts of North America" julcnx (talk) 12:06, 6 May 2026 (UTC)

Definition mixes material and method

The current definition combines a specific aggregate mix (material) with compaction (method), but this combination is not clearly scoped. If both are not required, `surface=compacted` can be interpreted broadly and used for well-maintained unpaved roads regardless of material. For example, the second image on the page could be interpreted as compacted dirt rather than an aggregate surface.

This is problematic, as compaction alone does not capture the underlying material. A compacted gravel, dirt, or clay surface can behave very differently, especially in wet conditions.

Additionally, it is unclear how to tag roads where an aggregate mix is present but no clear mechanical compaction has occurred (e.g. recently graded or loose surfaces). In such cases, the surface may not exhibit the stability typically associated with `compacted`.

Should the definition clarify whether both aggregate composition and compaction are strictly required?

Native soil tracks graded and rolled without any imported aggregate can be visually indistinguishable from crusher run in photos. Since compaction is a process not a material, the wiki should document observable distinguishing factors. Without this, consistent field application remains difficult. julcnx (talk) 13:16, 5 April 2026 (UTC)

The photo with the pothole shows some pebbles in the hole, but the top surface could be silt or clay, a mixture not be seen there. (I'd be curious how that behaves in wet conditions.) Obviously the surface has been compacted, if by developers or by mere use, impossible to tell from the photo alone. If I remember correctly, fine_gravel once upon a time was defined as "a compacted base with a thin layer of fine gravel on top", so this photo would the show the same with a thin layer of silt on top? BTW: What does "limerock" mean? (I can translate it, but I never seen something on location.)

Personally, I'd say, that compacted describes the base layer and not the "thin top layer". In my area the image from the header shows a really good example. (From the colour, the material contains a lot of limestone.) It is very easy to see through the thin top layer of fine gravel. I'd say something OSM mappers capable of in large numbers. Hungerburg (talk) 19:12, 6 April 2026 (UTC)

On limerock: a regional US term for processed oolitic limestone used as road base. Your point about the base vs. wearing surface distinction is useful, but it highlights rather than resolves the ambiguity: in many rural or lower-income contexts there is no engineered base layer, just graded local soil or laterite, and some mappers reach for surface=compacted too. The wiki not documenting any observable distinguishing factors, visible aggregate through the surface, camber, drainage, is what allows such wide interpretation. julcnx (talk) 16:05, 9 April 2026 (UTC)

I'd say, drainage the most essential detail to make a compacted surface stay in good shape. Get water off the there by crowning e.g. or a bottom layer of gravel to let the water sink down. A compacted surface soaked with water looses firmness like an animal its winter-coat. I observe that especially when super heavy logging trucks on the tracks in early spring. Hungerburg (talk) 20:28, 14 April 2026 (UTC)

Link to tracktype=grade2 based on firmness

The page associates `surface=compacted` with `tracktype=grade2`, which is primarily implied by firmness (mostly solid), not material.

While a compacted aggregate surface typically fits `grade2`, other surfaces such as compacted clay, laterite, or natural soils can also meet the same firmness criteria.

This suggests that the link to `tracktype=grade2` reflects surface condition rather than material, and is therefore not specific to `surface=compacted`.

Should this relationship be clarified as non-specific and based on firmness only? --julcnx (talk) 13:56, 2 April 2026 (UTC)

It is possible that many mappers can only recognize compacted using the additional construction cues some use for tracktype=grade2 (camber, ditches, embankments). The photos used to illustrate this type all have most of these features, and also relatively good smoothness, so mappers may also be using that as a cue too. I've seen many mappers referring to roads with compacted surface as being usable even under heavy rain and resisting rain well (but this doesn't help much in arid areas). --Fernando Trebien (talk) 11:51, 6 April 2026 (UTC)

Interesting point. If mappers are relying on indirect construction cues — camber, ditches, smoothness, rain resistance — rather than material composition, that would further support documenting these factors explicitly, as they are currently implicit at best. julcnx (talk) 09:25, 7 April 2026 (UTC)

Reword first sentence

The first sentence describes compacted as if it was a material, not a recipe how to create a reliably firm surface in all weather. The rationale perhaps: Bring it in line with other surface types, e.g. asphalt or concrete. Which are mixtures as well, not to forget that. But certainly much more accepted in colloquial speech. But going to a dealer, they certainly can offer material the lends itself very well to compaction. First sentence says:

surface=compacted is a mixture of coarser (e.g., gravel typically 20 mm) and finer (e.g., sand) aggregate, compacted (with a roller)

This is wrong: The material mix must also contain particles finer than sand, very fine particles so to say, silt and clay that is. Hungerburg (talk) 19:26, 6 April 2026 (UTC)

Agreed, the current sentence is wrong in two ways: it frames compacted as a material rather than a surface outcome, and it omits the silt/clay fines that are structurally essential for binding under compaction. Without that fraction a gravel/sand mix stays loose regardless of roller passes. A more accurate opener might be: "surface=compacted is an unpaved surface made from a well-graded aggregate mix — combining coarse particles (e.g. gravel ~20 mm), sand, and fine particles (silt or clay) — that has been mechanically compacted to form a stable, hard-wearing surface with more grip and firmness than loose gravel." --julcnx (talk) 16:03, 9 April 2026 (UTC)

Thank you! Just started a poll in the forums, independently of this here, as I was not notified. The fines are essential for compaction to be even possible, at least in terms used in construction. Lets see what the experts there come up with. --Hungerburg (talk) 20:19, 14 April 2026 (UTC)

The water-bound macadam article on Wikipedia makes this precise: Edgeworth's method "filled the gaps between the surface stones with a mixture of stone dust and water." That stone dust (the very fine fraction) is what enables binding under compaction, which is exactly the nullanteil point. Worth citing in the revised first sentence as a historical grounding. julcnx (talk) 14:16, 4 May 2026 (UTC)

suggestion fix: replace "it is sometimes known by its historical precedent as water-bound macadam" with "it is sometimes known by its historical precedent as water-bound macadam on Wikipedia; the fine fraction grading to zero (nullanteil) is what enables binding under compaction, not the rolling alone"; julcnx (talk) 12:11, 6 May 2026 (UTC)

Thin protective fine_gravel layer: tagging the return to compacted

Picking up Hungerburg's point above that "compacted describes the base layer and not the thin top layer": the degradation direction (compacted → loose) is covered, but the recovery direction is not. When a maintenance layer of fine gravel is freshly spread over a compacted base, the surface is surface=fine_gravel — particles shift under load. Once traffic works the loose material into the base and the surface is stable again, the tag should return to surface=compacted. The criterion is behavioral: does the surface shift under foot or wheel? julcnx (talk) 11:35, 6 May 2026 (UTC)

The criterion is already implicit in the definition: surface=fine_gravel is the correct tag for a loose wearing course that shifts under load, regardless of what lies beneath. Once traffic has worked the material in and the surface no longer shifts underfoot or under wheel, the observable test is met and surface=compacted applies again. Adding a sentence to the article to make the recovery direction explicit alongside the existing degradation guidance. julcnx (talk) 15:32, 12 May 2026 (UTC)

Should the definition require imported aggregate?

The current definition says "a mixture of coarse, fine and very fine mineral aggregate, typically mechanically compacted" but does not distinguish between imported aggregate and native soil that has been graded and rolled. A native-soil track graded and compacted with a motor grader can be visually indistinguishable from a crusher-run surface in dry conditions, yet the two can behave very differently when wet. Should the definition explicitly state that surface=compacted applies to surfaces built from imported or brought-in aggregate, reserving native-soil surfaces for surface=dirt, surface=ground, or a material-specific tag? julcnx (talk) 11:44, 6 May 2026 (UTC)

Requiring imported aggregate would make the tag unverifiable from the road surface, which is the same problem as requiring a roller. What makes a surface compacted is the particle size distribution: a mixture from dust to coarse gravel (0 to ~32 mm) where the fine fraction (silt or clay, grading to zero) acts as a binder. A road built from well-graded natural material (decomposed granite, moraine, naturally occurring laterite) can be visually and behaviorally indistinguishable from crusher-run in dry conditions, and both produce a stable bound surface. The tag documents surface state, not the construction supply chain. julcnx (talk) 15:24, 12 May 2026 (UTC)

Is mechanical rolling a strict requirement?

The definition says "typically mechanically compacted with a roller" but typically implies exceptions without stating what they are. Common cases where a stable surface exists without a roller pass include: graded aggregate consolidated by traffic over time, motor-grader passes that partially embed particles, and materials that self-stabilise through chemistry rather than pressure (e.g. lateritic soils hardened by iron-oxide cementation). Should the definition confirm whether rolling is strictly required — and if not, give an observable test (particles shift under load, surface saturates vs. drains) that does not depend on knowing the construction method? julcnx (talk) 06:58, 9 May 2026 (UTC)

The Finnish road administration manual on gravel road maintenance (Tie 1485, p. 13) addresses this directly for the wearing layer of a bound compacted road: "it is not economically worthwhile to use separate rubber-tired or smooth rollers. Satisfactory results are generally obtained by systematically driving back and forth with a truck while the wearing material is still at its optimal moistness." The same manual notes (§4.7) that "when good mineral aggregate is used, the wearing layer will become compact and hard." Compaction is an outcome of material composition and moisture, not of the specific tool used. Rolling is one method among several, not a defining criterion. I have edited the first sentence to remove the method clause and the unobservable "during construction or maintenance" timing, keeping only the observable outcome: fine particles bind the aggregate, the visible pieces become firmly embedded in the fine mass, and the resulting surface is reliably stable. julcnx (talk) 15:23, 12 May 2026 (UTC)