(Differentiation: see also Cycle_routes/cyclability )
I've used this tag for the classification of streets (especially the less cycle-friendly one's) according to the Cheltenham Cycle map standard. 1 is most bike-friendly, 5 is most bike un-friendly. Use it if you wish - at least I don't think it will conflict with other tags, and the information embedded is not normally in the database in some other way.
Notice: The Cheltenham Cycle map standard has a degree of subjectivity in it. This is probably intentional. If you know the "hard facts", you could probably enter shoulder width, maxspeed, cycleway, amount or cars etc ...
On the Uppsala Bicycle Map, bike-unfriendly roads are rendered with some diagonal stripes overlay. This information can come from both cyclability, or - lacking that - hazard tags, maxspeed, highway=primary classification.
New proposal tag to inform the cyclability of ways. Please note that this page was created by another contributor who uses his nomenclature described above.
|Definition:||Defines the cyclability is in 3 levels, good cyclability (grade A) acceptable cyclability (grade B) and cyclability inadvisable (grade C)|
- Good cyclability: a path that can work safely with a child on a bike, for example.
- Cyclability acceptable: a path that an experienced cyclist little flow.
- Cyclability inadvisable : a path that security conditions are not ideal for cycling, traffic, high speeds, Large goods vehicle presence, no shoulder
Have been chosen four key criteria: The speed limit on the road, traffic, lane width and safety felt. Speed was chosen as the basic criterion, others are qualitative.
- Legal speed: speed limit on the road
- Traffic: traffic density, presence of bus, HGV
- Width : can easily exceed the cyclist
- Security : topography, surface quality, no shoulder.
Alternative proposition to following table of above author: see please forum discussion started: at 
Leaving in Germany, where the definition of cycleways is matter of the legal text named shorted VWV StVO and very fine detailed in the ERA, I see other priorities. It is probably the same in all countries, where the law or conventions or precise recommendations with consumers organisations can manage this type of equipment:
Is the way in all points conform to the defined rules, it has certain or good level of quality!
More important can be the obligation to use ways not being conform to such a high quality level or not all the time free or being really very dependent of weather (not paved!).
I propose to use 1 (ONE) global index for cyclability:
Index value 0: The way is forbidden for that use!
Index value 1: No critic known about that licit way (probably a good way, perhaps a best way, but without sureness)
and to use following multiplier for those possible "degradations":
2 = obligation to use
3 = can be inaccessible (dependent of snow, forest or agricultural or mining activity, etc.: no clearance service)
5 = lack of consideration of rules and standards
7 = can be very dirty and slippy (not paved etc.)
11 = doubtful at night and in the dark.
Sharing with other users, direction, against traffic, obstacles, surface, smoothness have own keys (see Cycle_routes/cyclability )
Rendering: Ways lines become smaller if index increase / following the contour of the way with the mouse, the actual index appears in a little window (the even and odd and multiples of 5 are very recognizable and the user can discern multiple details simultaneously seeing this index)
|Tag||legal speed||positive qualitative value||cyclability||Example Picture|
|cyclability=good||10 / 30 km/h||0 to 3||Good (A)|
|cyclability=acceptable||50 km/h||3 (low traffic, correct width, good security)||acceptable (B)|
|cyclability=inadvisable||50 km/h||2||indvisable (C)|
|cyclability=inadvisable||50 km/h||1||indvisable (C)|
|cyclability=inadvisable||70 km/h||0 to 3||indvisable (C)}|