A discord discussion I had with ouchjars | OpenStreetMap lead to the Major Traffic Route in SA to be classed as Trunk Roads.
I was, and still am, against the notion that we have to copy road classification 1-to-1 from any source:
Data SA classifies roads in a way that doesn’t appear to neatly map on to OSM road heirarchy [me, 02/09/2023 23:08]
This was in reference to the first mass import you proposed, copying classifications from the Roads dataset. I pointed out inconsistencies in that data at the time, and it’s just been relitigated in your thread about Park Terrace and Gawler Street.
At most, I tentatively agreed with your proposal to classify all A roads as trunks, not the set of “Major Traffic Routes” designated in the Functional Hierarchy for South Australia’s Land Transport Network dataset.
The latter includes relatively minor roads like Fullarton Road and Richmond Road, but not e.g. Regency Road and Goodwood Road which are built to a higher standard and see equal or greater volumes of traffic (cf. Traffic Volumes dataset).
The former would be consistent with the Australian Tagging Guidelines as written, but now I have reservations about even doing that completely, as some A roads closely parallel other, more major A roads, e.g. Churchill Road/A22, Northcote Terrace, and Marion Road/A14.