This varies from state to state. In Victoria, as has been mentioned above, it’s a flat fee. In my home state of New South Wales, it’s a bit more complicated…
From when Adam first bought a car, up until the early 1990s, it was similar to Victoria. There were twelve insurance companies used by the government, and your car’s registration was assigned one at random. They all provided the exact same cover, for the exact same price, mandated by the state government (my memory is a bit hazy, but you might not even know which company you had - it didn’t matter to the individual). You paid your “third party personal injury” insurance as a component of your car registration when you fronted up at the RTA (DMV, DoT).
In 1992, or along there somewhere, a conservative state government introduced the current system. The twelve companies were now allowed to compete, and the individual car owner could choose. So, the RTA resistration cost dropped, but you had to bring along, in addition to a “pink slip” (mechanical roadworthiness certificate") a “green slip” (insurance certificate). The companies initially competed mostly on price, and registering a car became cheaper for a few years. Some companies also competed on product, and threw in a few extras on their policies. Needless to say, prices crept back up eventually. Also, the risk is no longer universal, eg. if you’re male, under thirty (or worse, under 25), drive a high-powered car, and have a poor driving history, you will pay big money (assuming you can find a company who will take you). Years ago, I had the embarrassment of being point blank refused insurance in front of a queue of people - I had a perfect driving history of a decade, and a pretty vanilla car. My crime? I was 28.
Under both the old and new systems, there are three main types of insurance:
- Third party personal injury (medical insurance for the guy you hit). This is COMPULSORY. Drive out onto (or even park on) a public street without it, and you’re in hot water if caught, because your car is unregistered.
- Third party property damage (for the Rolls Royce you hit). This is not compulsory, but even if you drive an old beater, it is insane not to have this.
- Comprehensive insurance (pays for the other guy’s car, but also your own if the accident is your fault. Also fire and theft).
I’ve actually got something between 2 and 3. Because I’m a pretty good driver (I like to think - my record says so, anyway) but my car is a piece of crap, I’ve got third party property damage plus fire and theft. So, the only thing I’m not insured for is my own car if I have an accident that’s my fault. Based on price, I’ve decided to carry that risk.