You have to use common sense, and if it dose not feel right on you fist visit, then you leave.
Human instinct is a great tool.
We use it constantly when we travel all over Australia and do many free camps in the outback.
You seen to know as soon as you stop if it feels safe.
We have never had a problem, and you know it is much safer to be 20 ks or so from any town, either side, not many ratbags lurk out that far, unless they intentionally drive out for trouble.
Leon