[talk-au] Australian Road Review by littlemaps

[Little Maps]

Hi Warren, thanks for your feedback. You sent me back to my computer to
re-check some numbers. Remember that the 57,828 kms in the blog post only
includes OSM highway tags from highway=motorway to highway=tertiary. Other
road types, including highway=unclassified, track, residential etc, are not
included in the totals. I just ran some Overpass Turbo queries to calculate
the total length of other road classes in WA, and this what you get:


OSM ROAD CLASS

DISTANCE (km)

CUMULATIVE TOTALS

Motorway to tertiary

57,828 (as in blog)

57,828

Unclassified

87,195

145,023

Track

77,339

222,362


If you add motorways to tertiary plus unclassified roads in OSM you get
145,023 kms. This is very close to the total length of roads that is not
managed by DPAW, as you quoted from the WA Main Roads report: 147,676 km.
In fact the difference is only 1.8%.

In addition to this, there are 77,339 kms of highway=track in WA in OSM.
This vastly exceeds the length of DPAW managed roads (National Parks,
Forestry) that you quoted from the WA Main Roads report (38,333 km). (I
assume that at least some of these "extra" tracks must be on private
property?) It's difficult to compare the numbers any more closely than
this, as Main Roads WA and OSM categorise roads in different ways.

Thus, the total length of highway=motorway + trunk + primary + secondary +
tertiary + track in WA in OSM = 222,362 km. The total length of roads that
are and are not managed by DPAW that you quoted from the WA Main Roads
report is 186,009 km. So I reckon OpenStreetMap is doing pretty well
really, *especially *on unsealed roads. (Plus, about 20,000 kms of
residential roads have also been mapped in WA, as well as other road types).

Having said all that, I'm sure that extra roads will be added to OSM in WA
and the NT, as you suggest. Northern Qld is probably in the same boat.
However, the total length of these roads will be very minor compared to
what's already been mapped.

Anyhow, thanks for keeping me honest, I'm glad I didn't stuff the numbers
up that badly!  Best wishes Ian :)

On Tue, Jun 22, 2021 at 6:54 PM Warren via Talk-au <
talk-au at openstreetmap.org> wrote:

> An impressive effort Ian but I think you have underestimated the length
> of Roads in WA.
>
>  From Main Roads WA report:
>
> Road length excluding DPAW managed  roads = 147,676
>
> DPAW managed Roads (National Parks, Forestry etc) = 38,333
>
> Mappers in WA have a long way to go.  I suspect a large percentage of
> the sealed roads have been mapped on OSM.  The remainder are almost all
> unsealed.
>
> The NT may be in a similar position.
>
> Nonetheless an interesting  report.  Thanks for sharing.
>
> Warren
>
>
>
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