Motor vehicle insurance, also called automotive insurance, a contract by which the insurer assumes the risk of any loss the owner or operator of a car may incur through damage to property or persons as the result of an accident. There are many specific forms of motor vehicle insurance, varying not only in the kinds of risk that they cover but also in the legal principles underlying them.
 Availability varies. Enrollment discount applies during data collection; final discount is calculated on driving behavior and could be zero. Discounts do not apply to all coverage elements; actual savings vary by state, coverage selections, rating factors and policy changes. Final discount applies at the next policy renewal and remains until drivers or vehicles on the policy change.
If the younger driver is covering his own costs, it might be cheaper for him to take out his own policy but include one of the older, lower risk drivers from the household as a named driver (as long as the older drive will use the car). However, if the older driver is footing the bill for both policies, multi-car insurance may still work out cheaper.
Several jurisdictions have experimented with a "pay-as-you-drive" insurance plan which utilizes either a tracking device in the vehicle or vehicle diagnostics. This would address issues of uninsured motorists by providing additional options and also charge based on the miles (kilometers) driven, which could theoretically increase the efficiency of the insurance, through streamlined collection.