[Tagging] Describe explicitly that values of highway tag do not imply anything about road quality (except highway=motorway and highway=motorway_link)

Lauri Kytömaa lkytomaa at gmail.com
Wed Aug 19 07:11:35 UTC 2015

Mateusz Konieczny wrote:
> quality. In area with poor infrastructure road forming main road
> network, of the highest importance in region should be tagged
> highway=trunk - no matter whatever is is high-quality asphalt road or
> unsurfaced tract unusable after major rains.

I generally agree on all the points you mentioned, but I had to
mention two points to this, one on a detail and the second on
what is it that the text should or shouldn't try to convey to the

1) I'd say that since "trunk" is the next best thing below
motorway, in any country (or "region") there has to be something
between motorway standards and "unsurfaced tract unusable
after major rains" - primary is a valid long distance road, too. I'm
not even saying a trunk road could't be unpaved, or that it couldn't
be repeatedly blocked "sometimes". I did ask on the wiki
highway=trunk tag discussion page in 2009 whether anyone knows
any roads marked as trunk in osm which are unpaved, and only
later read somewhere that south of Sahara most trunk roads are
unpaved, but in that discussion there was no mention of whether
they are (generally) "usable" after major rains.

I would however be confident enough to assume that no country,
no matter how underprivileged, doesn't have some longer distance
roads that are traversable after and during common adverse
conditions; then if other long distance roads are not equal, they'd
be a step down from that trunk level, even it the better roads do
not cover the whole country. This can, however, possibly, clash
with countries' own osm tagging guidelines if they only use some
administrative class as the base for what is a trunk and what
isn't - I don't know enough details about all the countries. Does
anyone have examples?

2) This gets a little philosophical, because it's about what makes a
road a road. It's somewhat misleading to write that the highway tag
doesn't say _anything_ about the quality, when it's easily read as
"doesn't say anything about the physical properties" - a road is,
IMO, by definition something that looks like a road and works like
a road (and in western world necessarily also: built as a road), not
any strip of land where somebody once drove through, so it does
describe the limits of what the physical properties can be expected
to be, i.e. the list of worst possible attributes that it needs to fulfill
for people call it a road. At the moment, I don't have a ready
sentence to add, but it's worth noting that the concept of "a road"
includes both usage and physical appearance.


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