As mentioned above most roads out that way are single lane bitumen - make sure you have ch-40 on to talk to / hear from oncoming traffic regarding on or off or sharing the bitumen
Road from Windorah is sealed for 110km to the Birdsville turnoff, then 275km of gravel from there on Here's a pic of the bitumen part of things
and the Birdsville gravel road ... pick any pair of wheel tracks and settle in for the ride :)
ps- we in the MH lowered tyre pressures from 60PSI to 40-45PSI for the run into Birdsville & back again, with cruising speeds from 60km/h to 75km/h being pretty usual. There is an excellent rest area half-way out to Birdsville at Deon's Lookout - tho it might be very crowded around Races time.
Hope this helps Phil
-- Edited by Ozzie_Traveller on Thursday 2nd of May 2019 08:10:33 PM