[OSM-talk] Classifying Ways worldwide (was: Numbers and i18n)

[Wollschaf]

On Thu, 03 Aug 2006 10:38:12 +0100, Etienne wrote:

> One problem with the waytype categorisation is that it tries to encode
> several physical attributes into one value.  It seems to combine the
> physical width and the number of lanes into one subjective key.

That is indeed a problem. The scheme itself is not very flexible. But it's
very easy to enter and remember. And - the problem vanishes is if it is
possible to override the standard values given by the scheme using
separate tags.

> If we are seeking a purely physical description of the roads then
> shouldn't there be a separate key for each aspect of the road.  The
> following would describe one carriageway of a motorway: lanes=3
> width=18m
> breakdown_lane=yes
> oneway=yes

That would be best, I agree. But how would you represent a road that is
just wide enough to let two cars pass each other? Should something like
lanes=1.5 be used?

Perhaps we should find the most common road types of the world and try to
describe the physical properties using seperate tags. We then could group
the most common cases into a single tagging scheme (name to be invented,
just like the waytype scheme) which sets certain default values for the
separate physical tags.

It would then be easy and fast to enter most roads (using just a
one-letter code to describe all physical properties), but also possible to
define entirely uncommon roads using separate tags - we would make the
common case fast, which is a good thing... only slightly unusual roads can
still use the classification scheme, and override certain properties using
single tags.

Wollschaf