[Tagging] Proposed rewrite Of highway=track wiki page

Bert -Araali- Van Opstal bert.araali.afritastic at gmail.com
Tue Mar 9 11:19:44 UTC 2021

On 09/03/2021 11:53, Mateusz Konieczny via Tagging wrote:
> Mar 9, 2021, 03:23 by bert.araali.afritastic at gmail.com:
>     On 09/03/2021 03:43, Kevin Kenny wrote:
>>     On Mon, Mar 8, 2021 at 6:10 PM Bert -Araali- Van Opstal
>>     <bert.araali.afritastic at gmail.com
>>     <mailto:bert.araali.afritastic at gmail.com>> wrote:
>>         Why do we need unclassified ? Look at it from the point of
>>         view from an ant, walking on the tree.  The ant only knows
>>         that it walks on a road, it can't see that far to see if that
>>         road is a minor branch or a major branch, or even a shallow
>>         trunk.  It does however know that it is something that
>>         belongs to one of these, because sap runs through it. It's
>>         like a mapper in the field without a satellite imagery. The
>>         ant can only find out what the road exactly is, by walking
>>         all the way from one end to the other, or by asking other
>>         ants who already acquired that knowledge.  In case they are
>>         not there, it should call it unclassified, to indicate it
>>         needs more information to assign a final judgement.
>>     That's not how it's used in OSM.  What you described is tagged in
>>     OSM as `highway=road`. `highway=unclassified`, misleadingly, is a
>>     formal read classification in the UK - the road is classified as
>>     an 'unclassified road'.  What 'unclassified' means is that the
>>     road has a lower importance than 'tertiary', but is not
>>     'residential', either because it is more important than the
>>     residential roads or because it serves another purpose such as
>>     accessing an industrial district. (If we were to start from a
>>     non-UK-centric perspective, we'd have probably chosen a tag like
>>     'quaternary' to describe this in a more neutral fashion.)
>     Maybe that's the most common way how it is interpreted in the
>     West, having it's roots in the UK.  In Africa, it's not. We
>     generally have very few or no highway=road. It also isn't
>     considered a valid classification in Highway Tag Africa guidelines.
> Which ones?
> Looking at https://wiki.openstreetmap.org/wiki/Highway_Tag_Africa 
> <https://wiki.openstreetmap.org/wiki/Highway_Tag_Africa>
> it describes highway=unclassified as
> "Minor collector roads that allow travel and commerce from paths and 
> residential
> roads to and between settlements. While generally not residential, 
> there can be houses along the road."
> what matches 
> https://wiki.openstreetmap.org/wiki/Tag:highway%3Dunclassified 
> <https://wiki.openstreetmap.org/wiki/Tag:highway%3Dunclassified>
> It also has "if you're in doubt of what tag to use, use highway=road"
> "In case they are not there, it should call it unclassified" is 
> mismatching general guidelines,
> general usage and Highway Tag Africa guidelines.
Very well noticed Mateusz, I surely expressed or used wrong terms here. 
Sorry for the confusion, it shows how mixing up terms causes so much 

Unclassified on Highway tag Africa is defined as the gap or void filler, 
and yes it refers also to highway=road.  What I wanted to say is that 
using both of these as gap or void filler, especially by mixing in other 
terms, doesn't make it clear, causes conflict with the track concept. 
That "unclassified" is not clearly defined on Highway Tag Africa as a 
nice delineated scope. Does not improve practical use.

"Minor collector roads" - what is a minor collector road ? Many attempts 
have been made to match the trunk/primary/secondary/tertiary 
classifications with the socio-economic classifications used by the 
National Authorities. Most of them use the trunk-strategic-arterial / 
Collector / Feeder / local terms.  When you try to do so or mix these 
terms in the definitions of primary/Secondary/Tertiary, I end up with 
Trunk & Primary =strategic-arterial, Secondary = collector or feeder and 
tertiary = collector or feeder.  So far I haven't found any nice 
explanation in the OSM wiki what this feeder / collector difference is.  
So you expect an OSM mapper to refer to the scientific literature or 
presume he must be an academic to be able to classify a road. As an open 
community I think we should be able and strive to do better.

If I look at one definition (Wikipedia which by no means is always fully 
correct, but used by many as "the" reference) of a collector road it 
says: "A *collector road* or *distributor road* is a 
low-to-moderate-capacity road <https://en.wikipedia.org/wiki/Road> which 
serves to move traffic from local streets 
<https://en.wikipedia.org/wiki/Street> to arterial roads 
<https://en.wikipedia.org/wiki/Arterial_roads>. Unlike arterials, 
collector roads are designed to provide access to residential 
<https://en.wikipedia.org/wiki/Residential_area> properties. Rarely, 
jurisdictions differentiate major and minor collector roads, the former 
being generally wider and busier."
All kinds of confusion grows here: low-to-moderate capacity, so it 
defines it in terms of throughput classification. As far as I am 
concerned any transport route that collects local traffic, no matter 
what it's capacity, width is a collector. Minor, do you mean minor in 
capacity, or narrower (mixing in it's phyical appearance). So here this 
creates lots of confusion, meaning paths cannot be collectors, narrow 
unimproved roads, tracks or streets whatever you want to call them are 
not collectors ?
"are designed to provide access to residential properties", so this 
means there are no collectors in industrial or sparsely populated rural 
areas ?
"travel and commerce from paths and residential roads". Now we mix in 
paths. So tracks never end on a collector ? A feeder never ends in a 
collector ? Is a feeder a secondary or a tertiary road in OSM, is a 
collector, used in it's definition a secondary or tertiary road ?

The Highway Tag Africa says "While generally not residential, there can 
be houses along the road." But we have houses along many of our roads or 
tracks.  Which makes them by definition residential.  Contradicts again 
with collector etc... etc... etc... And then if with this definition it 
isn't clear we should use highway=road, which makes it even more 
unclear, because the western world defines most of our roads as tracks 
because of their physical appearance = unpaved, in many cases narrow.

We included this to match the global "unclassified definition", which I 
thank Zeke to point me at that because it is much better, still not good 
enough (it mixes in motor vehicles, uses a mix of terms like streets, 
roads tracks, unpaved poor, rural etc...), we have some work to do, and 
for sure, Highway Tag Africa better fits our local infrastructure but is 
very poor in translating that form the global definition.

I am hoping, by better defining our documentation and some changes left 
and right we can come to a more clear highway tagging.  One that doesn't 
need to much local variants, it only creates more confusion, and as in 
Africa many Westerners are mapping that don't even know or respect local 
guideline. There should be no need to completely bend and redefine local 

I see good potential in the track as a base / tree concept for us to 
achieve this.


Bert Araali

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