On 13/08/19 02:02, Joseph Eisenberg wrote:
yopaseopor,
My initial question was really about Indonesia in particular, and
countries without established, official highway classification systems
in general.
But I took a look at Spain, and while I don't know much about the
local road system, the use of highway=trunk vs highway=primary looks
quite good!
See the current rendering around the city of Soria, Spain:
https://www.openstreetmap.org/#map=8/41.749/-2.444
https://www.openstreetmap.org/#map=7/41.500/-2.340
There is 1, and only 1, trunk road (or motorway) from Soria to each of
the 7 cities around it.
This is also true of Cordoba:
https://www.openstreetmap.org/#map=8/37.9875/-4.7763
And it looks like every place=city in Spain is connected by
highway=trunk or highway=motorway to all of the other cities. This
means you can render a map with just these 2 tags and place=city, and
have a complete national roadmap.
I actually think this is a great example of what I would like to see
in Indonesia.
In contrast, look at Toulouse, France:
https://www.openstreetmap.org/#map=7/43.588/1.384
- A highway peters out to the northeast (toward Lyon) and to the south
(toward Andorra). But if you zoom in to see the primary roads, it's
clear that the highway has switched from trunk to primary mid-route.
This makes it difficult to render a proper map.
I think your confusing tagging with rendering.
Tagging is what is on the ground.
The road from Toulouse toward Lyon may physically change between the two, so
the tagging follows that (I don't think so but as an example?).
Rendering then has to make choices. If the choice is simply based on the
tagging alone then there will be gaps,
particularly if those choices are made over large areas with various levels of
infrastructure.
If the choice includes determinations of making at least one road connection
from every city at some zoom level then you may have a 'better' map.
Similarly if the choice includes determining that little information is shown
over some area of the map at some zoom level and so more detail can be resolved
there you may have a 'better' map.
Each time these choices are made the complexity increases, if done manually
then each time the map is remade there will be time spent on it.
If done by computation then there will be some computer time on it and
occasionally errors will be encountered.
I have a road in one state at one level but when it crosses the state line it
changes as that state regards it as a lower level .. and
the road does deteriorate quite noticeably! The tagging is correct but most
maps show the road vanishing at one zoom level, you have to zoom in to see the
poorer road.
The present rendering 'rules' don't resolve these issues as they are simple
rules without too much complexity.
To get these rendering issues resolved will take some time, and more computer
time.
_______________________________________________
Tagging mailing list
Tagging@openstreetmap.org
https://lists.openstreetmap.org/listinfo/tagging
