[talk-au] highway=track update

Josh Marshall josh.p.marshall at gmail.com
Tue Feb 23 10:59:40 UTC 2021


This raises the question: how did the surface=gravel tag end up getting defined as large aggregate/railway ballast anyway, given it appears at odds with almost everyone’s usage of it, including other significant online references such as: https://en.wikipedia.org/wiki/Gravel_road (which matches the vernacular perfectly)?? Any OSM old-timers recall enough to comment? Is there actually anywhere in the world where roads are commonly done this way?

With regard to:
> 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. 
and Michael’s
> I don't map much in the US but do in Australia and Sweden. In both countries, I have rarely come across what I consider to be gravel roads, instead consider most unpaved roads and tracks to be 'dirt' or 'compacted':

Same here. I might provide a single counter-example; the major through road in the Watagans near me was actually lined with this large ballast last time I rode through; an absolute nightmare to ride on, and I can’t imagine it’s too kind on vehicles either. Presumably an initial step before further surfacing? Has anyone else seen this surface?



> On 23 Feb 2021, at 8:44 pm, Little Maps <mapslittle at gmail.com> 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. 
> 
> 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
> 
>> 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.
>> 
>> 
>> 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  <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 <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 <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
>> _______________________________________________
>> Talk-au mailing list
>> Talk-au at openstreetmap.org <mailto:Talk-au at openstreetmap.org>
>> https://lists.openstreetmap.org/listinfo/talk-au <https://lists.openstreetmap.org/listinfo/talk-au>
>> _______________________________________________
>> Talk-au mailing list
>> Talk-au at openstreetmap.org <mailto:Talk-au at openstreetmap.org>
>> https://lists.openstreetmap.org/listinfo/talk-au <https://lists.openstreetmap.org/listinfo/talk-au>

-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openstreetmap.org/pipermail/talk-au/attachments/20210223/5d420b97/attachment-0001.htm>


More information about the Talk-au mailing list