Proposed features/mtb:scale:amtb

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Proposal status: Proposed (under way)
Proposed by: JPinAR
Tagging: mtb:scale:amtb=*
Applies to: node, way, relation
Definition: Rating system for Adaptive Mountain Bike cyclists

Drafted on: 2021-11-22
RFC start: 2022-06-24
Public-images-osm logo.svg mtb:scale:amtb
Rating system for Adaptive Mountain Bike cyclists.
Group: Properties
Used on these elements
may be used on nodesmay be used on waysshould not be used on areasmay be used on relations
Useful combination
Status: unsupported “draft” statusHelp translate this into English!

[[Category:Key descriptions with status "unsupported “draft” statusHelp translate this into English!"|mtb:scale:amtb]]

Example of adaptive cycle and rider


A rating system developed by Jeremy P. McGhee of The UNPavement which has seen wide adoption within the US as a standard for adaptive mountain bikers. To best describe the system I'll use their words:

"This system is designed to answer one question for solo adaptive riders: Is support needed or not? For riders with support, it is intended to direct to the best trail experience. It is also graded on a curve, providing a rating of what MOST, not all, adaptive riders will encounter. Riders in the extremes of disability level, ability level and/or equipment capability, may need to shift the scale. For further information please consult our trail blog, our trail videos, recommended routes and your preferred trail information resource."

Similar to mtb:scale:imba=* this tagging would apply to node (maps and signed), way (portions of trails that may change in difficulty within a larger route), and routes (named routes than may join larger portions together broken out by things like crossings and bridges).


There really isn't that much to tell adaptive mountain bikers about their specific needs. A trail could be an easy (green) IMBA rating but not be wide enough, pass through trees that are too narrow, or had berms than don't work for adaptive use because of how gravity works differently for three wheels vs. two. I selected this based on similar rating of established MTB ratings like mtb:scale:imba=*, mtb:scale=*, and mtb:scale:uphill=*. Yet it is distinctive to this use case and the abbreviation has already gained wider adoption at places like TrailForks with requests for support at other MTB community websites.

Although aMTB looks a lot like MTB, that is kind of the point, and when seen in the context of mtb:scale:amtb=* some might need a moment to evaluate that MTB was not just listed twice and that something is distinct. I do expect the second MTB to be capitalized when possible to this point but even when it's not I believe it's clear enough.


aMTB Trail Difficulty Rating System
Tag / Category Challenge Support
mtb:scale:amtb=0 ADA pathway or flat road Suitable for manual wheelchair
mtb:scale:amtb=1 No challenges exist Support not needed
mtb:scale:amtb=2 Some challenges exist Support recommended
mtb:scale:amtb=3 Major challenged exist Support needed
No rating not suitable for aMTB

More specific tags


I will be adding these tags to trails in the NW Arkansas area but the best examples come from outside OpenStreetMaps as this same rating system has been adopted by TrailForks which although they are a 'walled garden' the rating system is no and is available of OSM use.

An interesting example would be Jesse's Last Stand this is a downhill trail which plenty wide and no real obstacles so this trail would be mtb:scale:amtb=1. However, to get to the top of this trail could require the use of Slaughter Pen Phase 1 Central Access and part of Tatamagouche which would be amtb=3. So it would require taking the two into account together that could and would require a complete replanning of such an adaptive ride.


This could be rendered similar to how IMBA and SAC scaled rating systems are. Based on way or route data. Although this is outside OpenStreetMaps I would direct users to Slaughter Pen Phase 1 in NW Arkansas or Whistler MTB park in British Columbia in both of these cases the Adaptive Cycling option is turned on and you can clearly see what trails can and cannot be ridden with or without assistance. This would open up similar viewing and rendering options to any OSM based platform for the adaptive cycling community at large.

Features/Pages affected

Definitively Mountain_biking, also will like have also use tagging references for mtb:scale:imba=*, mtb:scale=*, and mtb:scale:uphill=*

External discussions


Please comment on the discussion page.