I’ve written an overview of the patterns of major roads across Australia, based on OpenStreetMap data.

https://littlemaps692810600.wordpress.com/2021/06/21/australian-roads-in-openstreetmap/

There’s lots of colorful maps, charts and tables. It’s a deep dive that breaks down the total length of motorways, trunk, primary, secondary and tertiary roads in all Australian states, and the proportion of each that is paved and unpaved. (With a couple of local exceptions, virtually all of these roads now have surface tags.) It focuses on the patterns of the roads themselves, not tagging patterns.

So, if you’ve ever wondered: (1) what proportion of all major roads is unsealed and unsealed; (2) how the Tasmanian road network varies from that in other states; (3) where to find the longest, unpaved, trunk road in Australia; and (4) many other nerdy road facts, please take a read.