Okay, I composed a short mail explaining the topic and asking for comments on it. I take it that no one else did it before.
I think we should also contact some people who have more experience and voice in OSM about the ambiguities we found.
Maybe one of them is reading the topic right now? Please clear up the confusion.
Hi there,
Easy thing first: I have no plans to render highway=road. I treat that as a “work in progress” tag for aerial imagery sketching or when someone gave you a GPS trace and you know only they were in a car, and it’ll need to be converted to one of the other highway types for it to show up.
Then there’s the topic of highway=path, highway=*+bicycle=yes, highway=path+bicycle=designated, highway=footway+designation=public_bridleway and so on. Frankly I’ve lost track of the number of disagreements there are in the community about what they mean, and I’m at a complete loss as to what should be rendered. It’s completely crazy, and every time I see it discussed I see different conclusions being drawn. It’s a complete mess. At some point I may put together a list of things I think you can cycle on and work from that, but I really wish everyone who is doing the tagging would at least get on the same page and make my life easier!
Cheers,
Andy
Andy, the point is, no matter the conclusions, there will be always a significant number of people who won’t follow the rules, either by ignorance or plain oblivion.
I don’t believe that the mess can be cleaned up easily. Instead, the rendering could be flexible and include at least the sure things, like “bicycle=yes”, “bibycle=no”.
Cleaning up the mess completely would require either making every user know and use the guidelines or removing the possibility of tagging as one wishes…
Anyway, this doesn’t seem like it’s going to be cleaned up soon (I hope I’m mistaken on that), so changing the rendering rules could serve as a band-aid until things get fixed. I’m not sure how much time it would require. Days? weeks until the whole tileset gets updated?
There’s another thing one should keep in mind: A good cylcemap should NOT ONLY render ways which are suitable for biking. To navigate with a map one also needs information about other paths!
(One example: I use a rendered os-map on a Garmin Oregon. All streets/pahts without a name are in big red on this map, however the autobahn is barely visible. This is really confusing. An autobahn is a big visible thing in the landscape so you’re expecting to see it on the map when you’re crossing one. When I don’t see it I always think I’m on the wrong way. Same thing with the paths/footway/bridleways. When I’m standing at a crossing in the forrest and there are 5 ways which I could choose but my map only shows 3. How am I supposed to know which of the 5 I should take?)
Cheers
Thomas
Good points Thomas,
Been thinking of the same thing, but not really in the same aspect as you. Of course all the ways have to be rendered the question is at what level of detail. E.g. for autobahn you really only need to now that it’s there and where you can pass under/over it, so wou want the cycle ways to be alot more visible than they usually are…
I think this is most about how to simplify the map in the best way for bikes. If you use an paper map that simpification is important, but with computer you should be able to do adaptive rendering helping you see detail when you com closer… 
Of these having been mentioned in this topic, here’s my try with descriptions for various cases, some of which are obvious:
highway=track + bicycle=yes: mostly for other than cycling users and wide enough for two track vehicles, but known to be allowed and cyclable
highway=track without any bicycle=?: mostly for other than cycling users; cycling is not known to be forbidden or impossible but none has evaluated it
highway=track + bicycle=designated: shouldn’t be found - it’s then a cycleway (or path) with possibly agricultural=yes or motorcar=private or whatever.
highway=bridleway: a path/trail signed for horses; cycling and foot traffic is allowed if not implied otherwise per country defaults (if anyone supports them yet or ever)
highway=bridleway + foot=no + bicycle=no: continental signed bridleways (blue sign with a horse and rider) where only horses are allowed
highway=cycleway: mostly or signed for cycling. In some countries a foot=no is added or thought to be implied.
highway=cycleway + foot=no: mostly or signed for cycling with pedestrians known to be forbidden: presumably very good for cycling.
highway=cycleway + foot=designated: mostly or signed for cycling but equally signed for pedestrians, too. Should be good for cycling.
highway=cycleway + foot=yes: mostly or signed for cycling and pedestrians are allowed/tolerated, too. Should be good for cycling.
highway=cycleway + foot=designated + motorcar=destination: mostly or signed for cycling but equally signed for pedestrians, too and an allowance for motorcar owners living there. Should be good for cycling but motorcars encountered infrequently.
One could combine these with a bicycle=designated to distinguish between trails signed as “no motorized vehicles” vs. “cycleway/shared-use-cycle-and-footway”
highway=footway + bicycle=designated: mostly or signed for pedestrians but signed for cyclists, too; should be very rare (usually better as a cycleway) but the way is equally usable and allowed for both. Can be presumed to be good for cycling.
highway=footway + bicycle=yes: mostly or signed for pedestrians but allowed and “usable” for cyclist; either it’s a designated footway or something else makes it look less than a cycleway. Not optimal for cycling but usable.
highway=path + bicycle=yes + foot=designated: a way signposted for walking and that could have even more equally signed and tagged uses (skiing, snowmobile, …); otherwise equal to the previous line.
highway=path + bicycle=designated: a signed cycleway, most likely good for cycling - other countries/English guidelines recommend tagging as a cycleway with possibly foot=designated, foot=yes or foot=no depending on signage and country rules. Could have additional x=designated tags, for example snowmobile=designated or segway=designated
highway=path + bicycle=designated + foot=no: a signed cycleway with no pedestrians allowed; presumably very good for cycling
highway=path + bicycle=yes: not a real cycleway (nor a footway) but cycling is allowed and known to be not impossible.
highway=path + bicycle=yes + foot=yes: not a “real” footway but something where cycling and walking is allowed and possible.
highway=path + foot=yes and none of bicycle=?: something used for transportation, where cycling is not forbidden and might just be possible but none would call it cyclable; it’s not a proper road nor a track nor a footway (could be a tiny hiking trail or some obscure designated elephant/snowmobile/skiing trail)
highway=path and none of bicycle=? and none of foot=?: best example would be a snowmobile trail - little is visible in the summer - where cycling might be allowed and possible in theory but none would call it cyclable nor even a footway or usable on foot.
highway=path + bicycle=no: something used for transportation but it’s not a track nor a footway and cycling is impossible or forbidden
highway=path + bicycle=no + foot=yes: something used for transportation and usable on foot, but it’s not a track nor a footway; cycling is impossible or forbidden
Hmm, how should this be tagged:
“I’ve got this new track. I was there by foot and it wasn’t illegal. I didn’t look at bicycle signs or motorcycle signs as I was busy watching animals.”
Well you could probably provide more detail, but on that limited description and assuming that it clearly wasn’t a road, then I’d tag it as highway=footway + foot=yes with no bicycle reference until I’d had chance to check. Default if not specified for the access keys is unknown.
Yes, but what I really wanted to ask was: is there enough room for such partial knowledge in the proposal of alv?
Mostly just a footway. If you’re in your home country and you know the location (sidewalk/other urban light traffic route/countryside/forest…) you are likely to know if cycling is allowed on such ways and can choose accordingly. You’re likely to have a faint memory of the surroundings, i.e. if it was a built way (looks somewhat cyclable) or seemed uncyclable.
If you’re unsure (it seem likely in your opinion that there might have been a footway-sign (banning bicycles) somewhere but you didn’t pass it / note it or you’re not sure if the surface seemed cyclable), I’d choose the less allowing variant, a footway that is. If you remember encountering a motorcar, you’d probably assume it was a track.
Someone is likely to add the correct information later. A tag “FIXME=cycleway?” or equivalent won’t hurt, though, in places where you really don’t have enough information for a “educated guess”.
I don’t like the idea of writing that cycling isn’t allowed (“footway”) and then writing “Well, in fact I don’t know it” (“FIXME”). Partial knowledge about something can only be expressed as an addon to data structures like footway or cycleway, which seem to have been created having finished maps in mind, but not a continuous process of collecting information.
“path” for example is more appropriate to the collection process with it’s xxx=yes/no/designated/unknown, where “unknown” can be expressed by omitting the tag. (BTW “yes, but designation unknown” is missing.)
I strongly vote for giving the “unknowns” a first place consideration when creating new data structures or explaining old ones.