If you are on a road with two way traffic you will most likely be closer to the center line on the road if you are the driver than if you are the passenger. The reason for this is that the drivers seat and steering wheel are also on the opposite side of the vehicle compared to America. Think about it. Take your time. It's probably best to start out in an automatic car as the manual stick shift cars in Australia have the gears shifted with your left hand .
Police regularly check motorists' speed with radar and camera devices.
Australia has very strict drink-driving laws and random breath testing is conducted in all Australian States. The limit is only 0.05 compared with 0.08 to 0.1 in the United States. State laws stipulate that licences must be carried at all times when driving. Australia is a huge country. Please allow yourself plenty of time if you plan to drive around the country.