Two of the most important factors that go into determining the underwriting risk on motorized vehicles are: performance capability and retail cost. The most commonly available providers of auto insurance have underwriting restrictions against vehicles that are either designed to be capable of higher speeds and performance levels, or vehicles that retail above a certain dollar amount. Vehicles that are commonly considered luxury automobiles usually carry more expensive physical damage premiums because they are more expensive to replace. Vehicles that can be classified as high performance autos will carry higher premiums generally because there is greater opportunity for risky driving behavior. Motorcycle insurance may carry lower property-damage premiums because the risk of damage to other vehicles is minimal, yet have higher liability or personal-injury premiums, because motorcycle riders face different physical risks while on the road. Risk classification on automobiles also takes into account the statistical analysis of reported theft, accidents, and mechanical malfunction on every given year, make, and model of auto.
There are three states that do not have a private CTP scheme. In Victoria, the Transport Accident Commission provides CTP through a levy in the vehicle registration fee, known as the TAC charge. A similar scheme exists in Tasmania through the Motor Accidents Insurance Board. A similar scheme applies in Western Australia, through the Insurance Commission of Western Australia (ICWA).
Driving without the necessary insurance for that vehicle is an offence that can be prosecuted by the police and fines range from 841 to 3,287 euros. Police forces also have the power to seize a vehicle that does not have the necessary insurance in place, until the owner of the vehicle pays a fine and signs a new insurance policy. The same provision is applied when the vehicle is standing on a public road.
In New South Wales, each vehicle must be insured before it can be registered. It is often called a 'greenslip,' because of its colour. There are six licensed CTP insurers in New South Wales. Suncorp holds licences for GIO and AAMI and Allianz holds Allianz and CIC Allianz licences. The remaining two licences are held by QBE and NRMA Insurance (NRMA). APIA and Shannons and InsureMyRide insurance also supply CTP insurance licensed by GIO.