A couple of years ago I mapped a small mountain road. It is not a wide road (usually 2 cars cannot pass each other, unless for certain spots). The terrain consists of gravel, earth and/or grass. On one side you look upwards the mountain and on the other side, it’s down.
Some parts of the road are quite bad/dangerous. If you take certain turns not wide enough, you risk sliding down the mountain. How should those turns be tagged (ideally)?
Thanks in advance for any advice.
Around here a road like that might be tagged
highway=track
surface=ground
width=xx
smoothness=xx
If it’s more important than track make sure you include those other tags.
I’ve never seen specific curves tagged, but their’s probly some hazard tag you could put on them
We have hazard=curve(s), but that’s for signed curves. We generally don’t tag unsigned hazards, because it’s often very subjective. What might be hazardous for one person might be some other person’s walk in the park. The best thing you can do is to convince the local authorities to improve or at least sign the hazardous curves and then map the updated situation.
Thank you very much for your replies so far, appreciate it! I now noticed I did not provide enough context, apologies.
In general: the location we’re talking about is in Italy, Cuneo province. It’s a low-population area, not very touristic. Lots of roads don’t have lighting (little light polution).
There is a road (asfalted) off the main road, which leads to houses (maximum 20, approx.) on one side of the mountain. It takes me about 10-15 minutes by car, to reach the next split off “road” (which I am talking about).
That “road” is used by the people who live in the houses (approx. 2 or 3) it can reach, and agricultural vehicles. The road had some mud slides last year and luckily several locals made the road accessible again. One of the dangerous corners I’m talking about, was mentioned to the municipality, They put up a wooden stick (I guess about 5 cm wide, 5 cm long and 100 cm high), right next to the road as a ‘warning’.
The roads I mentioned don’t have street lights, and no guard rails. I don’t expect the municipality to have any money available for road signs (the juice will not be worth the squeeze). I estimate the chance of road signs becoming available close to zero percent.
P.S. I try not to put subjective informaition in OSM, so I already talked to several people and they agree that you need to be careful in those corners 
So for me, personally, I know of the dangers here, so I’m fine. But for other / new visitors, such dangers would be quite beneficial to know. So I thought making that information available asynchronously via OpenStreetMap would be the best way (and would add quality and real information to OSM).
bicycle=hell_yes ?
That is at least verifiable - any hazard tag that you add is not just based on your subjective opinion.
How would you tag such a “hazard warning” in a verifyable way …??.. hazard=stick ??
I don’t think that the stick is the hazard 
I’d have a look at taginfo and see what that suggested. Or overpass.
Sure, and I did not mean that 100% serious, but the question is, what does the stick verify …??.. nothing, it is just a stick.
Nevertheless I think in the given case a tag like hazard=dangerous_road would be acceptable, even if not explicitely signed.
Thank you all for your input, appreciate it a lot.
Although I was unable to find “dangerous_road” on the hazard wiki page ( Key:hazard - OpenStreetMap Wiki ), I’ve tagged the road as such. Mostly because the tag seems to exist looking at taginfo ( hazard=dangerous_road | Tags | OpenStreetMap Taginfo )
I don’t quite get why you want to mark the hazard? What you are describing sounds to me like that “road” is just an access road to a couple of houses/farms.
There is no chance someone is routed along the “road”, except he wants to reach one of the houses. If he wants to reach one of the houses, there is no alternative.
I would prefer to keep the hazard tags for actually signposted hazards.
Why is that? hazard is designed as objective tag, describing actual hazard signs. To use it just based on gutt feelings is not beneficial for the tag itself.
In that case, it was mentioned the hazard was signposted by a stick. A poor signposting, agreed, but one anyway. Hence I too find it acceptable to map it ay a signposted hazard.
There is no roadsign “dangerous road” as far as I know and the tag it is generic enough to avoid misinterpretation. It is not worse than smoothness=horrible or similar which are also “gut feeling” tags but in use worldwide.
+1