Talk:Key:sac scale

From OpenStreetMap Wiki
Jump to navigation Jump to search

Please see the proposals discussion page for the history of this key.


The table with the attributes references UIAA I under its T5 section. The approved proposal has "climbing of second grade" there. This must be corrected. For your explanation: T4 requires hands to get ahead, while UIAA I requires hands only for balancing. So T4 already requires more than UIAA I. The proposal is consequent there: after I comes II. I propose to leave away the wrong specification in the table, just like the original SAC text also does not specify a grade. This should be enough to prevent misunderstandings. Will be done tomorrow. --Hungerburg (talk) 19:37, 29 August 2020 (UTC) Did that, actually, use of hands to keep balance is in T3 already. --Hungerburg (talk) 19:02, 30 August 2020 (UTC)


I think it was premature (June 2020) to eliminate all references to visibility from the values table, even more than in the approved proposal. Where I do my mapping, only one in three or four paths carries both tags, mostly SAC scale only though, because, SAC scale (the SAC one) includes visibility, and the article here mentioned them for around 10 years. Perhaps they can be thought of as "default" values that can be overridden? The split in the proposal indeed was done one-to-one. --Hungerburg (talk) 08:28, 30 June 2020 (UTC)

Statistitics for the summer season 2020 are in (Austria/Tyrol): Quite an increase in calls for rescue, though fewer deaths. Hiking is driving up the numbers of calls. Number one problem is: people getting lost! I bet most of them had the best equipment, their store had on offer, one more reason to nix the "mountaineering boots" section. I also bet, they did NOT use to plan their journeys. Most of 'em did not suffer any injuries however. Rescue teams agree: Being exhausted and some clicks on your (smart)phone away from a heli makes you click. For a summary: orientation is essential when hiking, the SAC sac_scale mixes both not without reason.--Hungerburg (talk) 22:47, 28 October 2020 (UTC)
Having made some, hopefully non-controversial edits, this one remains. How to do about this unfortunate choice during proposal time, to split trail vis in a separate key. Moving it to "general remarks" might be too heavy a lift for some? What about those lots of underspecified trails?--Hungerburg (talk) 23:03, 25 November 2020 (UTC)

Fixed rope route (Klettersteig)

Resolved: Discussion moved to path Talk:Tag:highway=path

Using SAC_SCALE for some tracks to distinguish hikability?

I think it should be possible to use the sac_scale also for tracks. Many tracks (forestry use) in Austria are marked and designated also for hiking and the sac_scale=hiking should apply. Some 4-wheel drive/tractor use tracks may qualify in some parts for sac_scale=mountain_hiking. Main reason: Distinguish tracks that are made for hiking from other tracks. One could create a hiking map by including all ways that have a sac rating. In my case the whole mountain behind my house is covered with tracks, gravel roads in the forest of grade2-grade5 only a few links inbetween are paths. To indicate that the track is part of a hiking route the sac_scale should apply. Any thoughts or comments?

Nah, that defeats the purpose. Already right now sac_scale=hiking is a mess where you don't know at all what to expect. If there is a hiking route on a track, than create a relation for that hiking route.--Extremecarver 19:04, 6 October 2009 (UTC)
I suggest you use extension tags on your highway=track to show it is not a "common" track (if common means usable by a passanger car) For exemple : surface=* or/and smoothness=* or/and tracktype=* sletuffe 01:24, 11 October 2009 (UTC)
The idea is to tag some (definitely not all!) tracks for hiking so it may be recognized as hikeable track by a renderer focusing on a hiking map. If tracks are not marked as hikeable a renderer cannot distinguish between city area tracks and tracks commonly in use for hiking. This distinction works fine for (foot)paths it could also work for tracks.
Okay, I think I missunderstood. I though you wanted to show technical hikeability of tracks. Which, even in city area are hikeable. What you want looks like to emphasis tracks that are of interest to hikers ? If yes, the above comment by Extremecarver to create a route that joins several pieces of track/path/highway is a good solution. Or if the track is of interest but is not really part of any named/important route, don't do anything, the map representation of tracks and path is enough to show wich track connects nothing or which track lead to somewhere. sletuffe 14:58, 11 October 2009 (UTC)
I have still some objections: In my area there are hiking trails that include segments on residential roads, tracks and actually the minority of trails is of type path (because the farmers drive with tractors to fetch wood the paths all end up as tracks). In the forest areas there are only 5% paths and 95% tracks. 50% of the tracks are hiking trails with hiking signs. About one third(!!) of the tracks are dead end forestry roads that should be mapped but not associated with hiking. How would one distinguish a "Holzweg" (forestry road that is often a dead end) from a hiking way-segment? One could use the presence of a sac_scale tag as distinction that the path is part of a hiking network and that it leads somewhere. But maybe we should discuss a hiking=yes tag and a mtb=yes? I personally would reserve the "route" for hiking ways that have at least a name and that are long distance. How would one associate a sac_scale with a route if the included ways have different scales? Katzlbt 09:49, 14 November 2009 (UTC)
I understand the need, but don't feel it's the best way do deal with it. Because that would be using a hiking rating scale for something that is different from it's difficulty scale. However you'r hiking=yes (or preferably something more explicit) seams better to me. The dead end track case could left as is, as this is guessable directly from the data. An hiking_interest=no could still be add though sletuffe 14:02, 14 November 2009 (UTC)
I am looking for something positive to tag a track that has a hiking reference number. I agree that dead end tracks can be managed by an algorithm, though Osmarender cannot do that in XSLT. Katzlbt 21:30, 23 November 2009 (UTC)
BTW, there are definitely tracks that I would tag sac_scale=mountain_hiking for a fall hazard or inclination.Katzlbt 09:49, 14 November 2009 (UTC)
This is a completly different matter, that need comes much much closer to the existing use of sac_scale. Also I wonder what type of track could have fall hazard ! I still think a few track could compete for a sac_scale=hiking tag. But I'm not sure it's the best way to tag terrible tracks, other ideas welcome. sletuffe 14:02, 14 November 2009 (UTC)
I hiked a track grade5 close to 100% incline; on the one side you do not want to go off the track or you are dead (especially in the dark). The track was marked with a hiking number and I assigned mountain_hiking for suggesting good shoes and not taking kids there. The sac_scale serves as rating how easy the track is hikable and that it is a marked hiking way. How would you tag a hiking way that goes on a track and that has a hiking reference number? I am open to suggestions. Example: name=Hikingway, tracktype=grade3, highway=track, mtb:scale=0, ref=23 (hiking), mtb:ref=47, mtb:name=Magic Moutain Runde ;-) and ...? How could we tag the way to let a renderer distinguish it as marked hiking path? Katzlbt 21:30, 23 November 2009 (UTC)
I checked in the original text of SAC. It does not imply any kind of way but talks about inclination. So a "Weg" that is a track with steep inclination qualifies for mountain_hiking right away. The German "Weg" also means track not only path. sac=hiking is flat or slightly inclined and for sneakers. Specifically sac_scale=hiking says that you do not need a map to hike such a way. SAC Scale So from the original text SAC scale applied to tracks is no misuse at all.
Ad discussion of this topic in our local OSM group yielded that sac_scale should apply to tracks (although only the 2 lower rankings: hiking and mountain_hiking). A often seen pattern in the Alps is that a destination can be reached by foot as mountain_hiking (steep sloped track or path) and also as hiking on a forestry road alternative.


Resolved: Osmarender displays sac_scale=hiking in red. Citation developers: It is not a bug. It is intended this way. Katzlbt 07:10, 3 December 2009 (UTC)

Real world use

Resolved: misunderstandings clarified, SAC T1-6 scale replaced 3-graded scale in 2002

Is this revised SAC scale actually in use somewhere outside of OSM? I was hiking in Graubünden last week and both the maps and the signs use the old scale. Which of course is not so strange if at least 95% of all hiking paths around there would fall into the T1 and T2 categories. --Cartinus 10:37, 20 June 2010 (UTC)

Revised? I do not see that OSM's SAC scale is revised. But, yes 90% of all hiking ways fall into the first 2 categories.
AFAIK most paths in the BAW Bündner Wanderwege network will have either yellow or red-white-red lozenges/paint markings, and correspond to SAC 1 and 2. There are relatively few blue-white-blue trails (mainly in the National Park, for instance from Val Trupchun to Chamanna Cluazza, and I think the trail to summit of Piz Quattervals). Other routes to commonly ascended 3000ers are either only partially waymarked, and then usually with cairns (steinmaenner). Examples: Fluela Wisshorn N ridge(T4+/T5 or WS according to SummitPost), Fluela Schwarzhorn (T4 on SummitPost, seems overgraded, I'd have expected T3-), Piz Minschun (T4 perhaps), Piz Lischana (T4 for summit section). The SAC scale is for me a huge improvement over the old EB/BG grading as it gives a much better idea of what I am likely to encounter on the route. The scale is widely used on the web (e.g., SummitPost) and in many recent (last 5 years) books. SK53 14:00, 22 July 2010 (UTC)
Your reply and the more recent edits to this page confirm what I was getting at with my question. This tag is useless for most hikers. This should have been made clear from the start so people could have ignored it in stead of mistagging a "difficult" hike. As to the word revised in my original question: I didn't wrote the osm-tag was revised. The SAC scale itself was revised, it used to have three categories like the three colours in the tag description and the three line styles on most Swiss and Austrian hiking maps. --Cartinus 19:22, 16 December 2012 (UTC)

Hiking grade

I agree that the scale is a mountaineering scale, not a hiking scale. Hiking trails are pretty much all T1/T2, with a few T3-. At the low end, we might have something like:

  • Easy - Mostly level, no significant elevation gain, treadway well compacted, any walker can likely manage.
  • Easy+ - Not flat, but grades typically no more than 500 feet/mile (10%). No significant fall hazard, or rock scrambling that cannot be handled simply by stepping up.
  • Moderate - Grades 500-800 feet/mile (10-16%), inclines too steep for an unconditioned city person to handle comfortably. Typically no or minimal rock scrambling.
  • Moderate+ - Average grades fall in 'moderate' category, but challenging features (rocky, rooty, or muddy treadway; talus; water crossings; brief sections of higher grades) warrant a higher rating.
  • Strenuous - Grades in excess of 800 feet/mile (16%), significant rock scrambling, or challenging terrain (boulder fields, loose scree, wet trail, etc.) Limited exposure (typically less than a 3-metre fall) may be present.
  • Difficult - Sustained (multiple hours) steep grades or rock scrambles. Grades may exceed 1000 feet/mile (20%). Difficult fords. Fixed cables, chains. or ladders may be present. Rock scrambles may need hands for more than balance and require upper body strength to make progress. Leaping may be required. Shorter hikers may be at a disadvantage. Lethal exposures may be present.

All of these would fit within T1 and T2, with the exception that 'difficult' might cross over into T3. The grading of a trail might also be seasonal; I know of trails that are 'strenuous' in summer but require technical gear (and are therefore beyond what most would call 'hiking') in winter. A scale like this might avoid the problem of bringing Grandmother or the toddler on a 'moderate' or worse trail. While there is some room for judgment, objective criteria are offered. -- ke9tv 19:35, 8 April 2019 (UTC).

German translation

It was pretty clear that some phrases were machine-translated poorly. I've attempted to revise the translation to more idiomatic English. ke9tv 16:56, 25 May 2020 (UTC).


Resolved: Use and definition of colors clarified

I cannot find what the "Yellow - red - blue color scheme" is for. Is it used on Swiss Alpine CLub maps? SHould this be described on the wiki page? Thanks Mayeul 18:36, 16 December 2012 (UTC)

I have no ideas, maybe some maps edited by the SAC ? Whatever, I think we shouldn't talk about it on the page. Wiki pages are about tags, not how to render. Or only as a side note to say : "it is rendered here and there this or that way". sletuffe 19:16, 16 December 2012 (UTC)
Those are the colours used by the SAC on the signs. If you want to make that more clear in the text, be my guest. Just removing the info is not helpful. User:Cartinus
Okay. I just tought it wasn't bringing more information than the table juste bellow (duplicate information). sletuffe 19:52, 16 December 2012 (UTC)
These are standard colours used by the [W] Schweizer Wanderwege (not SAC) in association with cantonal authorities. The yellow trails are usually marked by yellow diamonds affixed to trees, stones, walls etc; the other two by red-white-red or blue-white-blue paint splashes. In a small number of places a difficult route may be marked by cairns (Steinmaenner). The colours & symbols are used on standard yellow footpath guideposts. Special hiking topo maps are produced by SwissTopo in asscciation with Schweizer Wanderwege which use the same colour scheme (e.g. [1] around Flims, Laax & the Ruinaulta (Rheinschlucht). The OeAV uses a scheme of red & black, more akin to ski grades, with black probably corresponding to T3 or T3sup upwards. Actual scheme colours & symbols are handled by distinct OSM tags. SK53 (talk) 12:00, 9 September 2021 (UTC)

controversy about verifiability

I've added a section about the controversy about this tag (Mainly because it is listed at verifiability). Those who want to propose solutions to that problem are welcome to talk about it here. sletuffe (talk) 18:06, 19 February 2015 (UTC)

Added a hint that it can help to contact the mapper who set the previous value before overwriting one if one thinks that the value is incorrect. This has worked well for me in the past and definitely makes the result a little more objective. PaulAmosKreiner (talk) 09:00, 1 September 2021 (UTC)

Err on the safe side

Please, what does that mean? If it means, to artificially inflate the grade, I'd like to disagree: Imagine users having hiked a T1,2,3 trail that is marked T4 and having no problems, the next time they go T5, because, you know, they made it easily? Will we have to introduce T9 soon?

it means if you are not sure which grade to use choose one that is not too easy even if it is not perfectly fitting. Your argument is valid but apart from human users there are also routers and those are not subject to this "experience bias" and must be prevented from routing eg wheelchair users to T1 or worse paths. RicoZ (talk) 20:37, 9 June 2020 (UTC)

@Rico - The example is not a good one, sac_scale=* is not a synonym for wheelchair=*; while wheelchair routers may be right to avoid any path that has sac_scale set at all, that does not tell us anything about the actual grade to use, it is plain irrelevant.
Besides, T2 is not "worse" than T1, there are even people that enjoy and search for T6 "hikes" (climbs, so to say.) Again, to "err on the safe side" will instil a false sense of their abilities in peoples minds, which may cause them to get into danger.

it was one of the many examples. highway=path is a really badly (raising never ending discussions) defined entity which is commonly used to map anything from a sidewalk on a major city avenues to bike and horse paths to extreme mountain paths. Other people like to use it to map highway=via_ferrata or climbing paths. Hence some caution is necessary to avoid that routing software designed mainly for urban areas accidentally routes unsuspecting pedestrians or wheelchair users to a difficult mountain path. As you say having any sac_scale at all should avoid that. But what do you do if you know it needs some sac_scale but are not sure which one? T0,T3 or T6? Or omit it altogether because you don't know which one? RicoZ (talk) 21:10, 10 June 2020 (UTC)

Hello RicoZ, (intentively not indenting further, column gets so tight) Probably, this is getting off-topic, but I too have a curiosity in routers. Recently, a new contestant went online and if you toy with the parameters, it will suggest several alternatives when tuning, eg. start with,11.410241,47.315606,11.398165&b=2&c=2&k1=en-US&k2=km - Rightly, it does not find anything suitable for wheelchair, the unsuspecting pedestrian route is ridiculous and does not even reach point B, the hiking route is dull, mostly track, but when told to use the shortest path, it will suggest a pleasant hike - probably steep, probably some hurdles, yet 90+% unpaved. Routers are getting smarter, and more complicated to use, btw.
The other point you made: What to do, if not certain? As sac_scale should only be used on paths explicitly available for hiking, there should be a signpost close by that has some indication, at least the trail should be described in a guide, to the same. Indeed, in my preference, so called informal paths must not have sac_scale, because there is nobody in charge to groom the path and keep the grade. Informal is gathering steam and it is a much better tag to advise routers, IMO. --Hungerburg (talk) 22:24, 10 June 2020 (UTC)

Informal paths are not the main problem but sac_scale can apply even to those. We do not require any kind of official designation and verification for sac_scale, otherwise it would be obviously usable only in Switzerland. As a result sac_scale is has limited verifiability which is a known problem but it is still considered useful despite this.
Official paths may have some officially assigned difficulty (many don't or it isn't signposted) but this usually is on some different, local scale incompatible with sac_scale and in many cases rather useless. I have met people in Val Pelino that were "tricked" into paths marked as "easy excursion" on the signpost. In some other place "easy excursion" could mean an easy excursion, not there. So which sac_scale value would you assign to "easy excursion"?
We could use local difficulty scales just as we use local scales for climbing but I believe there are many more local hiking scales than there are climbing scales so the result would not be very useful. RicoZ (talk) 22:35, 11 June 2020 (UTC)

Hmm, I think I see now. On the page I read the passage, "It is suggested not to use this tag on paths not used for hiking or climbing." You read "Consider using this for any paths that are not easily walkable" - You would be right, because what I read is only a suggestion. So I read the "approved proposal", and there it says: "Provide a classification scheme for hiking trails" and further talks about winning over "mountaineers". In my understanding, the "suggestion" matches the "approved proposal" so much better, that the other passage has to be yanked from the page.
As with any standard, when there are competing national/local standards, there should be a way to express one in terms of the other. If it is not possible, then do not use sac_scale! It is swiss, but not the proverbial swiss army knife. Localized wiki pages can offer that, some do.
I have not found Val Pelino on OSM; Probably "easy excursion" is an UIAA 3 climb? Then it must not have SAC_scale. --Hungerburg (talk) 23:05, 11 June 2020 (UTC)

When uncertain..

[2] : not all good intentions give good results. "Consult experienced guides".. I have experienced guides that did my day tour in 45 minutes. Not a good base for a classification. RicoZ (talk) 22:55, 18 June 2020 (UTC)

Hello Rico, A factor of 10 in your comparison is truly extraordinary, yet I do not see the argument. I am fairly certain, that the scale itself has been devised by experienced guides. So why should they not be trusted in its application? --Hungerburg (talk) 10:12, 19 June 2020 (UTC)
There are many more local guides and classification systems than OSM users mapping hiking paths which could result in a very inconsistent tagging. How is a local guide in Italy supposed to know the SAC scale anyway? Otoh if we let the OSM users map as described in the proposal each one may have a slight bias but it is much more likely that they will learn from each other and the error should be smaller. RicoZ (talk) 18:03, 20 June 2020 (UTC)

RicoZ, I am sick of the hatred you spew against this tag - Devise your own scheme and try to establish that. There you can be the self-appointed custodian, call it RicoZ_scale, let it max out where you max out, whatever‌. SAC_scale is well established not only on OSM. --Hungerburg (talk) 18:26, 20 June 2020 (UTC)

I have no hatred against this tag. I think it would be best to just leave the description as it was approved and served well for years because it seems any changes cause more controversy than improvement. RicoZ (talk) 19:25, 20 June 2020 (UTC)
From the conversation with you and the changelog entries of your edits I have learned, that you consider this a troll tag; You have changed the page, so it started to contradict the approved proposal; You have no manners in discussion neither, you always come up with completely irrelevant stuff. Please leave this page alone --Hungerburg (talk) 20:31, 20 June 2020 (UTC)
Sure - if you leave it alone. RicoZ (talk) 20:36, 20 June 2020 (UTC)
I would expect that an experienced guide would know what to expect from clients of various levels of ability. That's part of guiding. The fact that a guide can do a difficult route with ease doesn't mean that the guide will escort a novice there. ke9tv (talk) 13:01, 9 September 2021 (UTC)
Child at play? --Hungerburg (talk) 20:38, 20 June 2020 (UTC)

troll tag?

I think that it is not a trolltag, as highway=path can be used to mark also almost impassable and barely visible ways. So sac_scale is not redefining it, therefore it is not a trolltag.

Using sac_scale=difficult_alpine_hiking on a highway=residential bridge to mark it as a collapsed would be a trolltag, but it is rather not used in this way

-- trolltag term author, for what that is worth Mateusz Konieczny (talk) 23:02, 20 June 2020 (UTC)

moutaineering boots

I think, this section is mostly just romance and can be shortened a lot. Looking at the pictures for the values where they are said to be required, some can be trail-run in sandals, none show any ice. Instead the other passage about "alpine", that got removed recently, should not be regarded as omissible(, perhaps even chauvinist). A recent initiative by the local alpine club (some hundred thousands of members though) wants to establish that hikers are well aware of hazards and are consciously and successfully doing their best to prevail :) There is some real need for that, as officials are about to quarantine people into the lower mountain ranges or the pushchair ready highways around the cable car centres…

SAC Hiking Scale Revision 2020

The SAC published an English translation of its Mountain Hiking Scale in 2020 - It smells like machine translation, see - in places even unintelligible. I consider the wording on the article here much better, compact, concise, intelligible; it matches quite well the German version of the SAC publication from 2012. The revision introduces small changes in content too; The OSM definition better left as is. --Hungerburg (talk) 11:18, 24 September 2022 (UTC)

Use on relations

The info box specifies the key only available on ways. In practice, it is mostly used in a relation style, this recent change to the article text highlights that use, - I think, it would be better to allow use on relations and have the ways that constitute the relation tagged true to the ground. --Hungerburg (talk) 11:59, 4 November 2022 (UTC)

I don't think so. Not all ways of a route might have the same sac_scale or even no sac_scale. Would you say, that for instance the starting ways on a parking place and inside a residential area: sac_scale=demanding_mountain_hiking would be appropriate, just because the route relation has a tag that says so? Or do you mean: do not even think about following a hiking relation just because it has an inappropriate sac_scale for you (in total, complete length)? Even if you just want to follow only the first 30% (until a hut, restaurant, ...)