Shortest Route - Cairns to Melbourne

Interesting one Doug.
Assume via Charleville, you would start Cairns, Mt Surprise, Hughendon, Muttaburra, Barcaledine, Charleville?

So it is mainly dirt down the kennedy development road from the Lynd to Muttaburra. In good condition, you can almost sit on a 100, some places more. Some big dips though in the north at creeks, and with all of this rain, could be a bit dicey with some creek crossings and being cut up.
Once at Barcaldine, it is bitumen and 110k speed limit most of the way south through Bourke. Havn't tried that way through the Griffith area in southern NSW, so not sure the best way down there.

Roma, come down throught the coal fields, starting at Charters Towers, Mt Douglas. Havn't been on that road for a while, at least a decade or so. Is it all bitumen yet? If it is , a good run.

Safer bet with this rain might be the coast to Mackay or Rocky, then cut inland from there.

Ring the RACQ about the more inland route through Charleville for road conditions?

Sorry, the best I can do to help.

Just did a check on the RACQ web site for road conditions. www.racq.com.au.
The Kennedy development road from The Lynd to Hughendon is closed except for local light 4wds.
Same Hughendon to Muttaburra. That is good flat dirt road, remember sitting on 120 plus down that road once no problems in the dry. Different story in the wet though!

Looks like Tville, Charters Towers , Emerald best bet. Subjec to the rain.

Has been 20mm or more through that area in the last few days.

Ring the RACQ for an update.