Key:sac_scale

sac_scale
Description
A difficulty rating scheme for hiking trails
Group: Properties
Used on these elements
Implies
foot=yes
Useful combination
trail_visibility=* incline=* mtb:scale=* highway=path highway=track highway=footway
Status: approved
Tools for this tag
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The key sac_scale=* is used to classify hiking trails in mountainous areas with regard to the difficulties to be expected.

The scale discerns six grades in ascending level: From hiking (T1) up to difficult_alpine_hiking (T6). It is based on the Berg- und Alpinwanderskala des Schweizer Alpen-Club (SAC) (de).

All properties dealing with visibility of the path have been separated to trail_visibility=*

Applies to

A way which is tagged with one of the following:

• highway=path
• highway=track
• highway=footway

General notes

• Use this tag solely on ways used for hiking, as it solves a domain specific need. If local conditions cannot be expressed in terms of the SAC_scale, then do not use this tag.
• Tracks can carry a sac_scale=* tag if commonly (dual-)used for hiking or marked with hiking signs (Alpenverein, tourist authority). Then the sac_scale=* most likely will be hiking, or rarely mountain_hiking (if hazardous/slippery, map navigation required, etc.)

As the base description is a direct translation from the Swiss Alpine-Club publication, the scheme is primarily suited for mountainous areas. Other regions present other difficulties and requirements, and therefore other schemes might apply better. E.g a way in a flatland forest that is difficult to walk because of muddy ground or fallen trees does not classify for T2 ("mountain_hiking"). Other schemes need to be used to describe its condition.

Most hiking trails that are found in printed maps fall into the "hiking" and "mountain_hiking" categories. In low mountain ranges ways are often T1 ("hiking") only.

A note on mountaineering boots: Such boots are heavier and torsionally stiffer than the popular trekking or hiking boots. Ideally they make it comfortable to walk for hours with crampons, at least they make it easy to kick steps into snow crust or slippery soil. [1]

Values

Value	SAC scale and Swiss marking colour	Trail	Terrain	Requirements	Illustration
hiking	T1 yellow	Trail well cleared.	Terrain level or slightly inclined; no risk of falling with appropriate behaviour.	None. Can be hiked in ordinary sports shoes/trainers.
mountain_hiking	T2 white with red stripe	The trail is continuous with a steady ascent.	Terrain is steep in places and may have fall hazards.	Hiking shoes recommended Some sure footedness Elementary navigation skills
demanding_mountain_hiking	T3 white with red stripe	Exposed areas are ordinarily secured with ropes or chains. Use of hands may be needed for balance. Trail usually has markings.	Portions of the route exposed with danger of falling. Trail may have unmarked portions and cross fields of loose scree or talus.	Good sure-footedness Good hiking shoes Good navigation skills Basic mountaineering experience
alpine_hiking	T4 white with blue stripe	Use of hands may be necessary to advance.	Terrain quite exposed. Trail may include steep grassy pitches, talus slopes, easy snowfields, or snow-free glacier crossings	Familiarity with exposed terrain Robust hiking shoes (trekking boots) Some limited terrain assessment skills Confident navigation skills Mountaineering experience Sound weather assessment; weather may cut off retreat
demanding_alpine_hiking	T5 white with blue stripe	May include isolated easy climbing pitches.	Exposed and demanding terrain. May include steep rock scrambles, glaciers and snowfields with risk of sliding.	Mountaineering boots Reliable assessment of terrain and excellent navigation skills Good mountaineering experience Knowledge of elementary rope and ice axe techniques
difficult_alpine_hiking	T6 white with blue stripe	Includes climbing pitches up to UIAA grade II.	Severe exposure. Difficult craggy terain. Glaciers with high risk of sliding.	Mountaineering boots. Excellent terrain assessment and navigation skills. Proven mountaineering experience Familiarity with the handling of technical mountaineering equipment

The illustration images above have been provided by Marco Volken, member of the SAC trail classification working group.

Rendering

Tag	SAC scale (as seen on ground signs)		Alpine Paper Maps (Austria)
sac_scale=hiking	Yellow	T1		Solid red
sac_scale=mountain_hiking	Red	T2		Dashed red
sac_scale=demanding_mountain_hiking	Red	T3		Dotted red
sac_scale=alpine_hiking	Blue	T4		Dotted red
sac_scale=demanding_alpine_hiking	Blue	T5	(Not rendered)
sac_scale=difficult_alpine_hiking	Blue	T6	(Not rendered)

Controversy

Based on the guidelines of verifiability some people find this tag lacking of verifiablity. Please have a look at the discussion page at Talk:Proposed features/Hiking. As always on OSM you are free to use the tags you like. Before changing an already existing value, the mapper who set the prior value might be contacted.

Reasons to use it

• Especially for mountain trails, it is crucial to know whether a trail can be done in sneakers/trainers or whether you need an ice axe and crampons.
• Many commercial maps are not designed for hiking (because they denote only very few trails), this is a region where OSM can be of great value soon and for a long time.
• Many mountaineers already utilize GPSs. It would be great to win as many of them as possible as contributors to OSM.

See also

• Hiking
• Hiking Maps to see how this tag is rendered by OSM hiking maps
• Safety measures on hiking trails
• Proposed features/via ferrata
• JOSM Mappaint style
• Consider using incline=up/down to specify the direction of the way up or down the mountain.
• mtb:scale=* - a classification scheme for mountain bike trails
• Approved proposal for this tag