Hey all. Glad to have found this thread. I map a lot of mountain bike trails in Michigan (US) and for years I’ve been trying to best understand how to tag mountain bike trails. We have many MTB trail systems that connect to paved bicycle infrastructure (aka rail trails / multi-use paths) but are definitely not suitable for the traditional paved-path bikes.
This gets at where bicycle=designated and highway=cycleway is not appropriate for MTB trails. If MTB trails are tagged this way, pretty much every system out there sees them as cycling infrastructure and will route riders on them without them being aware they are MTB trails. This is undesirable, for obvious reasons.
For MTB trails in the US I’ve ended up with the following tags, and this seems most appropriate?
name=TrailName
mtb:scale:imba=0|1|2|3|4
oneway=yes|no|reversable
highway=path
bicycle=yes
foot=yes|no
horse=yes|no
segregated=no (only applicable if bicycle=yes and foot=yes)
surface=natural (optional)
bridge=yes (for short segments of bridge)
Then aggregate all of the ways into a relation for a given trail name. Then aggregate all of the trails in an area into a superroute for the riding area. With type=route, route=mtb, and ref= tags this conforms with tagging standards, renders very nicely in Waymarked Trails, Trailforks, on Garmin GPS units, etc.
As an example, the DTE Energy Foundation Trail has four loops, with each loop comprised of different main trails, some small connectors, and small pieces of winter-only trail routes.
The Superroute is here: https://www.openstreetmap.org/relation/6364861
This area can be seen in Waymarked Trails here: https://mtb.waymarkedtrails.org/#?map=14!42.355!-84.0845
The hardest part has been keeping editors who use iD, as this only tags things as highway=cycleway, meaning that a well-meaning person wishing to add a MTB trail but using iD will often create a route which is inadvertently tagged as a paved bikepath and requires cleanup.
As an example of this, just northeast of this system, across M52, is the Chelsea to Stockbridge B2B (aka B2B), a proper paved and designated footway/cycleway. Whenever DTE Trail gets tagged as Cycleway it’s then seen by mapping tools as equivalent to the B2B and paved-path navigation gets directed on to the DTE Trail.