TL;DR: We need to get a systematic measure of population density into
OSM to act as a guideline for mapping software to vary what goes at what
zoom level. This can be done either by adding the appropriately
calculated/derived density measure to admin boundary relations or, more
radically, as part of a separate Metabase where more arbitrary polygons
are allowed.
And now a bit of an essay:
For me, population size is the only meaningful indicator of relative
importance as it is quantitative albeit fuzzy (to me it doesn't really
matter whether it is for an admin area, urban envelope, metropolitan
area, whatever - if anything more rigorous is desired, use specialist
tagging).
But the rub is the word "relative". Relative to what? When I mapped
Dalby, Queensland in 2006/2007 the ABS population was below 10,000 which
in the then Brit-centric guidelines made it a village, which is
ridiculous given the importance of the town within the area.
So, I think some sort agreed national level hierarchy of populated place
is important in order to jive with cultural, legal, cultural and broad
population density criteria. But to vary it locally or regionally is
dangerous and I agree with cleary (if I am reading the quote levels right).
Graeme then says:
> ... but it would be good to do something that fixes the vast empty
when you cross the Great Dividing Range.
Yes. I think this is a map presentation issue not a map data issue. I
have a series of Android hobby apps published for specific areas and the
way I resolved it was to simply have a "low zoom" flag in some of them
which tells the map style sheet to show farms, hamlets and villages at
much lower zoom levels and with greater prominence at higher levels.
place=locality can also be a good one to pick out as can landuse or even
buildings. For Australia, specifically, my tip would be to
systematically tag main farm building(s) as place=farm or derive it from
named landuse=farmyard.
But that raises another question. Is there a generic way to generate a
"low zoom" flag? There are at least two possible solutions.
The first is to use the existing OSM data structure. Calculate or derive
(ABS??) population density for administrative areas and put it on
boundary relations, national, state and "local". It is then up to the
mapping software to see what is available and make zoom-level detailing
decision based on it. This is doable but makes things hard for the small
mapmaker like me to implement.
More democratic is to use a notion proposed by Sarah Houseman for
geocoding and I believe has much wider implication and is an important
step forward for OSM. I floated this at 2020 or 2021 SOTM. This is to
have a separate "metadata" database of polygons with, following OSM
practice, whatever you like attached to them.
The point of the polygons is that you can attach rules and hints to
them. They can follow legal jurisdiction boundaries or can be more
general. As an example "All of Western Australia except the Perth
metropolitan envelope". Or, outside this discussion, "the area where
xxxx is the main spoken language". Here are the three main areas that I
propose. (3) is relevant to this discussion.
(1) Rules. In the NSW polygon, bicycle=no where footpath=sidewalk except
for children under 16. In the Australia polygon, driving is to the left.
(2) Default hints. In the YYY polygon, surface=unpaved/paved where
highway=primary and surface tag not defined.
(3) Hints. Population density. Main spoken language(s). How addresses
are structured. ... and anything else that could be useful for mapping,
searching or routing in this area.
[Having such an open data, systematically structured database removes a
danger that map making moves back into the realm of companies with deep
pockets because only they have the resources to 1) collate the data, 2)
be able utilise it on the fly when presenting maps, routing, searching
based on OSM data.]
Mike
On 28/09/2023 04:04, Graeme Fitzpatrick wrote:
On Thu, 28 Sept 2023 at 11:25, cleary <o...@97k.com> wrote:
All valid arguments, thanks.
If everything is exaggerated so that villages are described as
towns and towns as cities etc., then I think it just devalues the
whole database on which the map is based.
I certainly see where you're coming from, but it would be good to do
something that fixes the vast empty when you cross the Great Dividing
Range: https://www.openstreetmap.org/#map=7/-27.163/145.569
I'll be interested to read comments from other mappers.
So would I, but so far there's apparently not too many interested in it?
Thanks
Graeme
On Thu, 28 Sep 2023, at 9:08 AM, Graeme Fitzpatrick wrote:
> Thanks!
>
> Yes, it probably shouldn't be a one size fits all equation.
>
> Against what you said, Rathdowney in SEQ, with ~1800 people,
only has a
> cafe / takeaway / store with a few grocery items, pub, currently
closed
> servo, all of police, RFS & (honourary) ambo, primary school,
church/s
> but it's a very popular day-trip tourist stop, so I would
definitely
> count it as a town.
>
> Most people travel 30k up the road to Beaudesert for a full
range of
> services, so that should possibly become a city?
>
> But Maroon, 20k the other way, with only a primary school & a RFS
> station, would only be a village.
>
> Thanks
>
> Graeme
>
>
> On Thu, 28 Sept 2023 at 08:26, cleary <o...@97k.com> wrote:
>>
>> I agree that population is not necessarily the only factor but,
in practice, population correlates closely with the services and
facilities available in a location which is effectively the
"relative importance", isn't it?
>>
>> I presume you are considering putting bigger dots and bigger
writing on the map for small settlements in isolated areas. Map
renderers can do that for themselves if they wish. It is more
important for OSM to show on-the-ground truth. If a small
settlement has few services, then showing it as a town is
misleading.
>>
>> Windorah Qld and Ivanhoe NSW are both currently shown as "town"
in OSM but neither has more than rudimentary health service (if
any), a hotel, small primary school and service station. I
couldn't buy a coffee in either place last time I visited. I don't
think either place had even a small supermarket or convenience
store. Unlikely to find a doctor. Probably wouldn't find a car
mechanic, couldn't buy a new tyre if you needed one. The locals
all travel a couple of hundred kilometres for shopping, health
care etc. I find it very misleading to label these places as
towns, just because they are the largest settlements in their
respective vicinities. The towns are the places where people go
to get the goods and services they need.
>>
>>
>>
>>
>>
>>
>>
>> On Wed, 27 Sep 2023, at 2:18 PM, Graeme Fitzpatrick wrote:
>> > Have just raised this for discussion on both the Forum &
Discord, so
>> > also throwing it out here.
>> >
>> >
https://wiki.openstreetmap.org/wiki/Talk:Australian_Tagging_Guidelines#Tagging_towns_by_relative_importance%2C_not_just_population_size
>> >
>> > Any thoughts or comments welcome, in any place!
>> >
>> > Thanks
>> >
>> > Graeme
>> > _______________________________________________
>> > Talk-au mailing list
>> > Talk-au@openstreetmap.org
>> > https://lists.openstreetmap.org/listinfo/talk-au
>>
>> _______________________________________________
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