[Tagging] Clarification unclassified vs residential

[Greg Troxel]

The real problem is that if unclassified is more important than
residential, what to do with roads that do not merit unclassified but do
not have primarily residential landuse?



As I see it, in the United States unclassified and residential are
equally important.  However, this is likely to be seen differently by
people especially from the UK, and the tagging scheme carries baggage
in terms of default assumptions about how the world is.

(Leaving out motorways entirely because they seem easy.)

In the UK, we hear about A, B and C roads, and that is encoded in
primary/secondary/tertiary.  We adapt that to roads in other countries
that do not have A/B/C signs.

In the UK, there are also roads that are actually signed as
unclassified, such as "U1274" (wrong number, but I remember an actual
road in Scotland).  There, it seemed there were villages (or towns - not
sure what they call them) that are compact (with 30 mph signs) and then
"not in town" (with circle/slash signs).   I have the impression,
perhaps incorrectly, that roads in villages are "residential" and roads
not in villages are unclassified as a default assumption.

In the US, while we do have more and less congested areas, the notion of
"is this road residential" is often fuzzy.

Then, there are urban roads that aren't particularly important but have
businesses rather than houses.

So all in all I'd say the entire unclassified/residential scheme doesn't
really fit the non-UK world exactly right.  (Really, it's remarkable we
have so little trouble in internationalizing tagging, but then again I
live in "New England", called that for a reason.)

Part of the difficulty is that in the US we use route designators much
more sparingly.  In Massachusetts, we have state highways, which are
sort of like B roads (vs US highway A roads), but we do not have
numbered county roads.  So many roads with merely names are tertiary
because they are how you go from one town to the next.  (Other states do
number county roads.)

One fix would be to declare unclassified more important in the road
network than residential but less than tertiary.  And to add a
road=minor that is exactly equal in important to residential but does
not imply that the preponderance of use is residential.

Or, we could retag residential to minor, as residential landuse can be
encoded with landuse polygons.

Or, use residential to mean minor and ignore the house bit.

Finally, I'd suggest in the US treating unclassified and residential as
exactly the same in importance, because we have no real notion of
unclassified roads like the UK.   That does mean renderers have to treat
them this way, at least in countries that go this way.   (Certainly a
renderer could treat an unclassied road with "ref=U1274" as more
important, as a general practice of emphasizing roads with refs.")