On Thu, Apr 2, 2020 at 5:12 AM Volker Schmidt <vosc...@gmail.com> wrote: > > If a highway is mtb:scale=2 it is definitely not a cycleway. It is a > highway=path with mtb:scale=2 > If this were to encounter a "cycleway" with mtb:scale=2 , I would consider > this an error and retag it as highway=path without hesitation. > > I agree, that this is not explicitly stated in the bicycle wiki page, and > should be added there, but I would assume that this is the common > understanding. Anything else would cause major problems with the huge stock > of existing highway=cycleway in OSM that have no mtb:scale tag. Routers for > non-MTB bicycles would all need to change and evaluate the mtb:scale tag. > > There is already a similar problem with the OpenCycleMap rendering in the > sense that it renders a dedicated cycle path in the same way as a path with > bicycle=yes. This has the effect that many MTB friends have added bicycle=yes > to "normal" hiking paths to make them appear as MTB friendly on the map, but > also with the problem that when I look at that map I wrongly see a cycle > paths where I would never be able to pass with my loaded touring bike. > > Please keep paths that can only be used by MTB clearly different from > cycleways that can be used non-MTB bicycles.
A key issue is that mtb:scale can't be the only indication. Otherwise, we're falling into a trap - which has been a common trap in the past. It's a trolltag https://wiki.openstreetmap.org/wiki/Trolltag - a second tag that negates or massively changes the meaning of another tag. "This isn't what you were expecting of a highway=cycleway: it's a wilderness trail for highly skilled and adventurous MTB riders!" Just as bad, though, is the fact that tagging with an mtb:scale requires technical knowledge of that specific sport. How do I tag, "this trail is posted for MTB use, and would be impassable to a road bike?" I pretty routinely map trails in wild forest areas. Some of these (a minority, in the places I go) allow MTB riding; others allow horses, a very few allow snowmobiles; most are foot- (snowshoe-, ski-) only. I'm a reasonably skilled hiker (calibration: I've done at least one 200+ km solo trip through the Adirondack Mountains in New York, sometimes pushing as far as 30 km from the nearest highway). If I'm using a grading system that I understand, I can come up with a pretty usable rating for a hiking trail. I'm not a mountain bike rider. If I were to assign a definitive scale, I'd get it wrong and possibly put riders at risk. All I know is that these trails are full of rocks and roots and not for a road bike. I don't think there's a combination of tags that lets me map what I know (bikes lawful, impassable to a road bike) without needing detailed knowledge that I don't have. We do indeed have back-country trails around here that are reserved for cycling - not recommended (or off limits) for hiking. https://www.mtbproject.com/trail/7017547/elm-ridge-loop is an example - it's an area that has about 40 km of singletrack reserved for MTB in the summer and x-c ski in the winter, not in a purpose-built MTB park, but in a Wild Forest area. I don't map those trails. As I said, I'm not an MTB rider, and there are places I like better in the winter. We also, of course, have multilple-use trails, and I've mapped a few of those - and probably messed up the cycling stuff badly. At least I've tagged 'smoothness' values in the range of 'very_bad' to 'impassable' on the shared paths. Even looking at that scale on the wiki, though, I ask things like: what's a 'trekking bike'? Something a US cyclist would call a 'hybrid' or a 'gravel grinder'? This general category: http://www.cyclingabout.com/wp-content/uploads/2014/01/wpid-Photo-29-Jan-2014-1144-am.jpg ? Straying from the topic: Assuming that anyone interested in tagging a feature will have detailed knowledge of one particular use is a recurring problem. We have the same issue with whitewater. I've paddled some whitewater, but I'm surely not competent to grade a stretch of rapids. OSM doesn't appear to have sound tagging for "there are rapids in the river here" that would allow mapping by someone who isn't a canoeist or kayaker. And don't even get me started on sac_scale, where the higher grades are technical mountaineering, and no longer hiking - at least as I understand the scale. My understanding is that the Swiss grade 3 is roughly comparable to French grade 3, or UK 'moderate severe' - which corresponds to about 5.5 on the Yosemite scale and is something that I surely wouldn't do without a rope! Those who are familiar with the scale tell met that this lady is on a Grade 2 trail: http://www.flickr.com/photos/65793193@N00/3072631007/ https://www.flickr.com/photos/65793193@N00/3183604743/ https://www.flickr.com/photos/65793193@N00/3183606625/ http://www.flickr.com/photos/65793193@N00/3183604309/ On the Yosemite scale, it's pretty much a Class 3+/4. It's hikable, indeed, it's blazed as a hiking trail. Nevertheless, there are some pretty dramatic fall hazards and a less experienced party or a group in adverse conditions may appreciate a rope.There are a couple of moves in the 5.4-5.5 range to get up it, but the exposed stuff isn't difficult and the difficult stuff isn't exposed. On the scale at https://appalachiantrailtravelguide.com/wv/ - much more suitable as a hiking scale - it's about a 9, maybe a 10. -- 73 de ke9tv/2, Kevin _______________________________________________ Tagging mailing list Tagging@openstreetmap.org https://lists.openstreetmap.org/listinfo/tagging
