I live in Perth (the capital of Western Australia not the UK one) I'm 20 minutes drive from the city centre, 15 minutes drive to wonderful beaches, and 10 minutes drives in several directions to bushland remote enough that if I had a heart attack while walking they would never find the body.
Australia is a big empty place, your biggest dangers (apart from hitting a roo, or dozing off and driving into oncoming road trains (single lane 110kmph YAY)) is not making it to the next petrol station. Its ok in urban areas, but as soon as you leave metro... better make sure you know your fuel efficiency.
But if you do stray off a main road, even by accident, its not like there is any space to turn around. Up in shark bay we pulled off onto a beach carpark and went down a sudden incline over the shells. No way to turn back and the only way was forward and hope the loop put you back somewhere else. Long story short sedan started to bottom out so we lost our nerve and tried to turn around. Big mistake, soon as we left the compressed trail we sank to the chassis at all 4 wheels. No reception, had hike through the bush back to the main road to hail a tourist bus to get the townsite to send out a truck to pull us out.