Assuming or defining a default should be based on the number of
different values within the set.
For the examples you give:
maxspeed shouldn't have a default. Apart from on motorway classed roads,
speed limits varies depending on local topography. There will be too
many exceptions to the rule.
driving_side is defined nationally so has a default. (I'm sure now
someone will now provide examples where that's not the case). Any
router worth its salt, should be able to check which country it is in.
On 31/08/2017 12:49, André Pirard wrote:
Examples: either each road is tagged with *maxspeed*=*
<https://wiki.openstreetmap.org/wiki/Key:maxspeed> speed limit and
<https://wiki.openstreetmap.org/wiki/Key:driving_side> or there are
I'm reviving this remark because the examples are numerous:
* The Belgian Flemish community wants to tag *maxspeed*=*
<https://wiki.openstreetmap.org/wiki/Key:maxspeed> on every road
instead of using a default. Is this a new specification and where
is it written? Must that now be done in every country?
* The current language= proposition wants to do it without defining
defaults. Really? language= on every name= ?
* Other examples are maxheight in tunnels. Osmose just accused me of
someone else's omitting maxheight. It shouldn't be necessary if
it's the default, that is if there is no sign for it, but Osmose
likes to yell just in case.
* countless etc.
Either the defaults are in the OSM database and it takes just a
routinely map fetch to get them all updated timely,
or each other router (GPS) writer implements them each their own way
from various random other files. It's not well clear how contributors
ca update all those files instead of OSM and it typically needs a full
software update for each little default change, depending on writer's
There is a Proposed_features/Defaults
puts the defaults in OSM and it's an EXTREMELY HUGE mistake to have
marked such a paramount good work as abandoned because nobody
continued the work. For the sake of OSM, especially routing, please
I don't claim that it is the good solution but I do claim we should
work on such a default database *in priority*.
I didn't analyze it in full depth, but I have the following remarks:
- Why not allow the def keyword in the border relation itself? But it
could be called zzdef to cluster at the key end.
- If a separate relation is preferred, it should be pointed at by a
"defaults" role in the corresponding border or other relations so that
it can be found.
- to ease scanning a border tree upwards, a "parent" relation should
exist in border relations.
In hope of a well structured OSM,
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