I have a radio in my 4WD for communication with the Rangers and other users. Channel 40 is the common frequency for most users, though the Rangers and I switch to 18 sometimes if we have a lot to talk about (such as monitoring a fire) and to get less radio traffic from others. It is also a good frequency to use to keep in contact when exploring in convoy. We can chatter away without interference and without interfering with others.
Driving back from Turkey Creek I heard a road train ahead of us announcing its approach to a one lane bridge. “Southbound approaching Stony Creek bridge”. This lets the other traffic know to get out of the way because road trains do not stop in a hurry. Whether officially or not, I am not sure, but they have right of way. An emergency stop for a road train is highly likely to result in a nasty road-blocking (or bridge-blocking) pile up.
I am still waiting to learn what should happen when two road trains approach the same bridge from opposite directions. A bridge out of Broom was blocked for two days when two road trains jammed themselves together trying to cross at the same time. It is usual for a train to have three trailers, and not too uncommon to be towing a fourth and occasionally even a fifth half-size unit too.
Unlike in NZ, no particular direction is designated as having right of way over here. It seems one is expected to judge whether one is closer to the bridge than the oncoming vehicle, and make a decision whether to give way or to proceed.
I later heard the same trucker announcing that he had just passed two wobblers heading north. Shortly afterwards, we passed the caravan-towing grey nomad tourists to which he was referring. They also use channel 40. I wonder how they feel about being designated as “wobblers”.