[Tagging] Highway mistagging ... again

Kevin Kenny kevin.b.kenny at gmail.com
Sat May 30 15:49:48 UTC 2020


On Sat, May 30, 2020 at 4:44 AM Alan Mackie <aamackie at gmail.com> wrote:
> I think part of the problem with the highway=track description is that even when you are there on the ground it isn't always clear what it's being used for. They are often two ruts in the ground disappearing of into the distance with little else to go on. If you then look at aerial imagery you may see that is goes to a single house and re-tag as driveway or that it serves multiple buildings and guess at whether the buildings lean towards highway=residential, highway=service or highway=unclassified. It's easy to say "primarily agricultural or forestry" but this is often rather difficult to verify.

And likely, no user cares very much. When it's just two ruts going off
into the distance, if it's part of the road network (you use it to
access multiple establishments or as a connection between other roads)
it's probably an `unclassified` highway.  If it's used just to get to
a house or two, it's a driveway. If it's used for mining, quarrying,
or similar industrial uses, or to access facilities like boat
launches, it's a service way. If it's used for farming or forestry,
it's a track. Except for 'unclassified', which is a hint to a router
that this is the way to multiple places, the only people who actually
care what sort of establishment the track serves are the residents,
workers, customers and guests of the respective establishments. They
already know why the road is there! Sure, if you know the reason the
road was built and want to map it, go ahead, but recognize that it
doesn't really tell people all that much.

> There is then a separate problem in that OSM-carto, the default 'check that it worked' renderer, doesn't render road surfaces or tracktypes for anything other than tracks. This discourages the 'proper' tagging for those who want to tell at a glance how likely they are to get their car stuck or how likely it is that they will be able to do a three point turn if there are obstructions.
>
> Tangentially, I have always found the tracktypes a little difficult to apply if you don't have the type of soil depicted in the examples. Some ground tends to get "lumpier" rather than softer if you keep using it without improvement.

Hmm. I don't think I've ever tagged a tracktype. When I'm trying to be
careful about the details, I tag surface and smooothness, add width if
it looks to be a problem for turning around, and hope for the best. I
also have occasionally used an unpopular and unwikified value like
`surface=shale`.  That can be very rough and lumpy indeed when it's
laid, but over time the shale weathers to smaller flakes of stone
mixed with fine clay, and in dry weather a shale road can offer a fine
compacted surface that doesn't even need to be rolled that often.

As far as I can tell, `tracktype` is mostly intended for surface
firmness: how likely are you to sink if you drive it in wet weather?
If I'm not doing a field survey in mud season, it's hard to tell.
Everythiing from grade3 to grade5 will have vegetation growing on it.
In the ruts, I'll see at least some hard material because the soil
around here is stony.  (Around here, too, grade1 is likely to be at
least `highway=service`, since nobody troubles to seal a track that's
used just for tractors or logging trucks.) I also don't see a lot of
ways with `tracktype` in my part of the world, so I don't have good
local examples to go on.
-- 
73 de ke9tv/2, Kevin



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