Tags

Tags #

Tags are key-value pairs that define objects. They are written as KEY=VALUE.

Some keys have a prefix or suffix. For example, mtb:scale:imba contains the key scale, which is prefixed with mtb to indicate the scale is for mountain biking and suffixed with imba to specify the IMBA trail classification system.

In general, OpenStreetMap discourages multi-value keys. Avoid setting multiple values for the keys using semicolons (`surface=grass;dirt`). Prefer single-value keys that most accurately describe the object.

highway #

The highway key identifies a way as a travel path. This includes roads, trails, and more.

Value Description
path Used for general travel. No specific travel method is determined.
cycleway Used primarily for bicycles.
footway Used primarily for foot traffic.
track Used primarily for traffic that services agriculture or forestry. Not intended for general travel.
The value assigned to the `highway` key does not necessarily restrict the use of bicycles. Other travel methods may be permitted. Refer to the value assigned to the `bicycle` key to determine what is permissible.

bicycle #

The bicycle key denotes whether bicycle traffic is permitted. The values yes, no, and designated are most common.

Value Description
yes Bicycle traffic is permitted. In contrast to designated, the value yes denotes that bicycle traffic is permitted, despite lacking clear indication.
no Bicycle traffic is not permitted.
designated Bicycle traffic is permitted, and this is clearly indicated.
private Bicycle traffic is permitted for some individuals only. For example, by employees.
permissive Bicycle traffic is not expicitly permitted. However, bicycle traffic is tolerated.
dismount Bicycle traffic is not permitted. However, bicycles are permitted if the rider dismounts and pushes the bicycle.
When choosing between `yes` and `designated`, remember that the `designated` value denotes that bicycle traffic is explicitly permitted, generally through signage.

The foot key denotes whether foot traffic is permitted.

Value Description
yes Foot traffic is permitted. In contrast to designated, the value yes denotes that foot traffic is permitted, despite lacking clear indication.
no Foot traffic is not permitted.
designated Foot traffic is permitted, and this is clearly indicated.
private Foot traffic is permitted for some individuals only. For example, by employees.
permissive Foot traffic is not expicitly permitted. However, foot traffic is tolerated.

surface #

The surface key describes the composition of a way.

Value Description
ground A general surface that covers many surface compositions. Prefer a more specific value over ground.
sand
gravel
grass
dirt
compacted A general surface that is mechanically compacted into a stable surface.
The `surface` key accepts many more values. The previous values are most relevant to mountain biking.

smoothness #

The smoothness key describes the condition and usability of a way by wheeled vehicles. In contrast to the surface key, the smoothness key does not describe the composition of a way.

Value Description
excellent A perfectly smooth way in excellent repair.
good A smooth way with minor wear.
intermediate A way with notable wear. May pose issues for some wheeled vehicles.
bad A way with major wear. Wheeled vehicles should exercise caution.
very_bad A way that requires 4WD with high clearance.
horrible Even 4WD vehicles with high clearance should exercise caution.
very_horrible Should be avoided by all wheeled vehicles.
impassable No travel advised for any wheeled vehicle.

Mountain bikers should reconsider travel if a way has a smoothness value of horrible, very_horrible, or impassable.

tracktype #

The tracktype key classifies the surface of a way as a grade. The tracktype key is often used with the tag highway=track.

In contrast to the surface key, the tracktype key does not describe the composition of a way. In contrast to the smoothness key, the tracktype key does not focus on wheeled vehicles.

Value Description
grade1
grade2
grade3
grade4
grade5

trail_visibility #

The trail_visibility key describes how easy or difficult it is to recognize a way.

Value Description
excellent Little to no chance of losing track.
good Easy to stay on track.
intermediate Be aware. Possible to lose track.
bad Easy to lose track.
horrible At times nothing. no markers. no indication.
no Mayben othing. No markers. No indication.

oneway #

The oneway key denotes whether traffic on a way is required to flow in one direction.

The oneway key is sometimes paired with the suffix bicycle to form the key oneway:bicylce. This may indicate a trail requires one-way traffic for bicycles, but other traffic may be two-way.

Value Description
yes Traffic for the way travels in one direction.
no Traffic for the way travels in any direction.

roundtrip #

The roundtrip key denotes whether the way starts and ends in the same location.

Value Description
yes The way starts and ends in the same general location. The way is a loop.
no The way starts in one location and ends in another. The way is not a loop.

The mtb prefix #

Mountain biking and cycling differ in many ways. The mtb prefix adds mountain biking-specific context to tags.

mtb:scale #

The mtb:scale key classifies the difficulty level of a way as a grade. The grade scale is based on a German Singletrail-Skala scale system.

Value Description
0 Accessible to most riders. Trail surface is packed and predictable. Expect slight inclines and no obstructions.
1 Accessible to most riders. Trail surface may be loose at times. Expect mild inclines and few obstacles.
2 Accessible to experienced riders. Trail surface is or otherwise challenging. Expect moderate inclines and frequent obstacles.
3 Accessible to advanced riders. Expect steep inclines.
4 Accessible to expert riders. Expect very steep inclines.
5 Prohibitive access, even to the most expert riders. Exceptional control required. Expect extreme inclines.
6 Inaccessible to non-professional riders. Trail may completely disappear. Expect extreme inclines and dangerous conditions.

mtb:scale:imba #

The mtb:scale:imba key uses the IMBA scale system. This system is commonly used in North America.

Value Description
0
1
2
3
4

mtb:scale:uphill #

The mtb:scale:uphill key uses a general grade scale to describe the uphill grade. Refer to the following image for a visual representation of grade:

Image 02 *Image credit: Trailism trail grades

Value Description
0
1
2
3
4
5

mtb:description #

The mtb:description key contains additional information about a way that:

  • Is specific to mountain biking
  • Can not be described adequately using tags

For example, mtb:description may be used to warn riders about challenging conditions of a trail: mtb:description=Parts of this trail are extremely dangerous after a heavy rain.

Value Description
Any string A plain text description that provides additional context.

Examples #

The images in this section were created using generative AI.

Logging road #

Image 02

This image depicts a logging road that passes through the forest. There are potholes in the road, but they are shallow.

Keys #

Key Value
highway track
bicycle yes
surface dirt
smoothness good
trail_visibility excellent
mtb:scale 1

Breakdown #

  • highway=track:
  • bicycle=yes:
  • surface=dirt:
  • smoothness=good:
  • trail_visibility=excellent:
  • mtb:scale=1:

Beginner trail #

Image 01

This image depicts a forest trail. The trail is well-maintained and features trail markers.

Keys #

Key Value
highway path
bicycle yes
surface dirt
smoothness intermediate
trail_visibility excellent
mtb:scale 1
mtb:description May become challenging after rain.

Breakdown #

  • highway=path: The way is a general use path. This is a common tag for biking trails.
  • bicycle=yes: Bicycle traffic is permitted. However, note the value is not designated. Foot traffic and other travel methods are also allowed.
  • surface=dirt and smoothness=intermediate: The trail is well-maintained trail. However, tree roots degrade the trail smoothness. As a result, the value intermediate is used instead of good.
  • trail_visibility=excellent: The trail is easy to follow. The visibility is enhanced by the prominent trail marker.
  • mtb:scale=1: Due to the roots in the trail, the value is increased to 1.

Mountain trail #

Image 03

This image depicts a challenging mountain trail. The trail surface is rocky. A fallen branch blocks the trail.

Mountain trail #

Key Value
highway path
bicycle yes
surface stone
smoothness good
trail_visibility good
mtb:scale:imba 3
mtb:description Beware of rock overhang. Low maintenance trail. Expect some obstacles.

Breakdown #

  • highway=path:
  • bicycle=yes:
  • surface=stone and smoothness=good:
  • trail_visibility=good:
  • |mtb:scale:imba=3:

Landslide #

Image 05

This image depicts a muddy trail that has collapsed due to a landslide.

Keys #

Key Value
highway path
bicycle yes
surface dirt
smoothness impassable
trail_visibility good
mtb:scale:uphill
mtb:description Danger! Do not use this trail until it is rerouted. A landslide has ruined several portions of the trailing, leaving them impassable.

Breakdown #

  • highway=path:
  • bicycle=yes:
  • surface=dirt:
  • smoothness=impassable: Prior to the landslide, the trail appeared to be well-maintained. However, the landslide makes the trail dangerous for use by wheeled vehicles. Until the trail is rerouted, the value impassable is assigned.
  • trail_visibility=good:
  • mtb:scale=uphill:
  • mtb=description:

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