[talk-au] highway=track update

[Warin]

On 23/2/21 8:44 pm, Little Maps wrote:
> Hi Josh and co, I ride a “gravel bike” on dirt roads that are 
> signposted as “gravel road”but definitely don’t fit the OSM definition 
> of gravel = railway ballast. Because of the common usage of gravel as 
> a variably textured dirt road in Australia, we face a massive uphill 
> battle to get accurate, specific unpaved road surfaces in OSM. Here’s 
> some data from Overpass Turbo queries of all unpaved highway surfaces 
> in Victoria. This includes all highway tags (inc roads and paths) not 
> just tracks:
>
> Surface 	   Number 	       Percent
> unpaved 	48664 	80
> gravel 	6159 	10
> dirt 	4559 	8
> compacted 	642 	1.1
> sand 	406 	1
> fine_gravel 	230 	0.4
> earth 	46 	0
> Total 	60706 	100
>
>
> In case that’s illegible, if you add all of these unpaved/dirt/gravel 
> ways, 80% are tagged with a generic unpaved tag (which is entirely 
> accurate if not especially precise). Gravel is the next most common 
> category, accounting for 10% of ways. Apart from dirt at 8%, the rest 
> are used very rarely.
>
> My guess from tagging surfaces on a lot of unpaved roads is that 
> perhaps 80% of the roads tagged as gravel do not satisfy the OSM wiki 
> definition and should be tagged as something else. Interestingly, the 
> two most relevant tags for formed, unpaved surfaces - compacted and 
> fine_gravel - are very rarely used (around 1% each). There are 
> probably more ways that have fence-sitting tags like “dirt; sand; 
> gravel” that end up being pretty meaningless.
>
> Adding precise surface tags may be simple on roads that are freshly 
> maintained but on roads that haven’t been maintained for a while 
> they’re often pretty difficult to assess anyway.


My take is that unpaved road surfaces change quickly and I don't want to 
be fussed with too much detail. So I tend to map then as unpaved. I 
think it more important to map the 'smoothness' (or roughness) of the 
road if it is certain it will stay that way for some time.

I do note that bulldust is not used... fine_sand is about as close as I 
saw. Usually these are short stretches. They can disappear after road 
maintenance... but reappear after some time, if you do see them mapped 
.. please leave them!

>
> Personally, I feel that there’s often too much emphasis in OSM on 
> precision (i.e. use detailed sub-tags) at the expense of accuracy. I 
> believe most of the generic unpaved tags are accurate. I wish I could, 
> but unfortunately I don’t believe many of the specific sub-tags are 
> especially useful. (Sand is a goody though!). Cheers Ian


I do wish that the sand depth was available.. and in some instances the 
gravel depth! I have come across a number of people who have had trouble 
with their vehicles tyres riding in trenches while the vehicle 
floor/diffs dragged through the road center. Those army mercs with their 
drop axles can build up a lot of depth without any worry to them!

>
>> On 23 Feb 2021, at 5:22 pm, Josh Marshall <josh.p.marshall at gmail.com> 
>> wrote:
>>
>> 
>>
>>     The approved OSM tag for surface=gravel
>>     <https://wiki.openstreetmap.org/wiki/Key:surface> refers to
>>     railway ballast, not the fine crushed rock or natural surface
>>     that usually occurs on unpaved roads in Australia. However we
>>     call the fine unpaved surface "gravel" in common parlance, and
>>     many unpaved roads that don't constitute gravel as described in
>>     the OSM wiki have been tagged as gravel here, erroneously
>>     depending on your point of view.
>>
>>
>> This is a matter of interest to me too. I spend a substantial amount 
>> of time running+riding on fire trails in NSW (all highway=track), and 
>> the surface type is useful and indeed used in a number of the route 
>> planners I use. I have changed a few roads back to 'unpaved' from 
>> 'gravel' due to the rule of following the description in the surface= 
>> guidelines rather than the name.
>>
>> My question then however, is exactly what to tag the tracks beyond 
>> "unpaved".
>>
>> There are definitely sections that are somewhat regularly graded and 
>> appear to have extra aggregate/fine gravel added. From the surface= 
>> wiki, these most closely align with surface=compacted. But 
>> fine_gravel is potentially an option too. Many of these are 2wd 
>> accessible when it is dry. (Typically smoothness=bad.)
>>
>> There are also others, usually less travelled, which are bare rock, 
>> clay, dirt, sand, whatever was there. Is it best just to leave these 
>> as surface=unpaved, and add a smoothness=very_bad or horrible tag? 
>> None of the surface= tags really seem to apply.


For bicycle travel while smoothness is useful so too would be a grading 
of required bicycle tyre width!

>>
>>
>> On Tue, 23 Feb 2021 at 16:45, Little Maps <mapslittle at gmail.com 
>> <mailto:mapslittle at gmail.com>> wrote:
>>
>>     Hi Brian and co, in Victoria and southern NSW where I've edited a
>>     lot of roads, highway=track is nearly totally confined to dirt
>>     roads in forested areas, as described in the Aus tagging
>>     guidelines, viz: " highway=track Gravel fire trails, forest
>>     drives, 4WD trails and similar roads. Gravel roads connecting
>>     towns etc. should be tagged as appropriate (secondary, tertiary
>>     or unclassified), along with the surface=unpaved or more specific
>>     surface=* tag."
>>
>>     In your US-chat someone wrote, "...in the USA, "most" roads that
>>     "most" people encounter (around here, in my experience, YMMV...)
>>     are surface=paved. Gravel or dirt roads are certainly found, but
>>     they are less and less common." By contrast, in regional
>>     Australia, most small roads are unpaved/dirt/gravel.
>>
>>     In SE Australia, public roads in agricultural areas that are
>>     unpaved/dirt/gravel/etc are usually tagged as
>>     highway=unclassified (or tertiary etc), not highway=track. There
>>     are some exceptions in some small regions (for example in the
>>     Rutherglen area in NE Victoria) where really poor, rough 'double
>>     track' tracks on public road easements have systematically been
>>     tagged with highway=track rather than highway=unclassified. See
>>     here for example:
>>     https://www.openstreetmap.org/#map=13/-36.1424/146.3683 .
>>     However, this is not the norm in SE Australia and across the
>>     border in southern NSW, this type of road is nearly always tagged
>>     as unclassified, as it is elsewhere in Victoria. In SE Australia,
>>     my experience is that tracks are tagged in the more traditional
>>     way, and not as has been done in the USA.
>>
>>     If I could ask you a related question, what do you US mappers
>>     call "gravel"? The approved OSM tag for surface=gravel
>>     <https://wiki.openstreetmap.org/wiki/Key:surface> refers to
>>     railway ballast, not the fine crushed rock or natural surface
>>     that usually occurs on unpaved roads in Australia. However we
>>     call the fine unpaved surface "gravel" in common parlance, and
>>     many unpaved roads that don't constitute gravel as described in
>>     the OSM wiki have been tagged as gravel here, erroneously
>>     depending on your point of view. How do you use the
>>     surface=gravel tag in the USA? Cheers Ian
>>
>>     On Tue, Feb 23, 2021 at 2:49 PM Brian M. Sperlongano
>>     <zelonewolf at gmail.com <mailto:zelonewolf at gmail.com>> wrote:
>>
>>         Hello all,
>>
>>         Recently, there was a discussion on the talk-us list
>>         regarding how we use the tag highway=track. That discussion
>>         begins here:
>>         https://lists.openstreetmap.org/pipermail/talk-us/2021-February/020878.html
>>
>>         During that discussion, someone suggested that Australian
>>         mappers may also be using the highway=track tag in a similar
>>         way to US mappers.  Hence this message :)
>>
>>         I've recently made edits to the wiki page for highway=track
>>         describing how the tag is used in the USA:
>>
>>         https://wiki.openstreetmap.org/wiki/Tag:highway%3Dtrack#Usage_in_the_United_States
>>
>>         If there is similarly a local variation in how this tag is
>>         used, I would encourage the Australian community to document
>>         their usage as well.
>>
>>         Brian Sperlongano
>>         Rhode Island, USA
>>

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