Odometer-based systems

Cents Per Mile Now[23] (1986) advocates classified odometer-mile rates, a type of usage-based insurance. After the company's risk factors have been applied, and the customer has accepted the per-mile rate offered, then customers buy prepaid miles of insurance protection as needed, like buying gallons of gasoline (litres of petrol). Insurance automatically ends when the odometer limit (recorded on the car's insurance ID card) is reached, unless more distance is bought. Customers keep track of miles on their own odometer to know when to buy more. The company does no after-the-fact billing of the customer, and the customer doesn't have to estimate a "future annual mileage" figure for the company to obtain a discount. In the event of a traffic stop, an officer could easily verify that the insurance is current, by comparing the figure on the insurance card to that on the odometer.

Critics point out the possibility of cheating the system by odometer tampering. Although the newer electronic odometers are difficult to roll back, they can still be defeated by disconnecting the odometer wires and reconnecting them later. However, as the Cents Per Mile Now website points out:

As a practical matter, resetting odometers requires equipment plus expertise that makes stealing insurance risky and uneconomical. For example, to steal 20,000 miles [32,200 km] of continuous protection while paying for only the 2000 in the 35000 to 37000 range on the odometer, the resetting would have to be done at least nine times, to keep the odometer reading within the narrow 2,000-mile [3,200 km] covered range. There are also powerful legal deterrents to this way of stealing insurance protection. Odometers have always served as the measuring device for resale value, rental and leasing charges, warranty limits, mechanical breakdown insurance, and cents-per-mile tax deductions or reimbursements for business or government travel. Odometer tampering, detected during claim processing, voids the insurance and, under decades-old state and federal law, is punishable by heavy fines and jail.

Under the cents-per-mile system, rewards for driving less are delivered automatically, without the need for administratively cumbersome and costly GPS technology. Uniform per-mile exposure measurement for the first time provides the basis for statistically valid rate classes. Insurer premium income automatically keeps pace with increases or decreases in driving activity, cutting back on resulting insurer demand for rate increases and preventing today's windfalls to insurers, when decreased driving activity lowers costs but not premiums

Reasonable distance estimation

Another important factor in determining car-insurance premiums involves the annual mileage put on the vehicle, and for what reason. Driving to and from work every day at a specified distance, especially in urban areas where common traffic routes are known, presents different risks than how a retiree who does not work any longer may use their vehicle. Common practice has been that this information was provided solely by the insured person, but some insurance providers have started to collect regular odometer readings to verify the risk.

Distance

Some car insurance plans do not differentiate in regard to how much the car is used. There are however low-mileage discounts offered by some insurance providers. Other methods of differentiation would include: over-road distance between the ordinary residence of a subject and their ordinary, daily destinations.

Vehicle classification

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.

Marital status

Statistics show that married drivers average fewer accidents than the rest of the population so policy owners who are married often receive lower premiums than single persons

U.S. driving history

In most U.S. states, moving violations, including running red lights and speeding, assess points on a driver's driving record. Since more points indicate an increased risk of future violations, insurance companies periodically review drivers' records, and may raise premiums accordingly. Rating practices, such as debit for a poor driving history, are not dictated by law. Many insurers allow one moving violation every three to five years before increasing premiums. Accidents affect insurance premiums similarly. Depending on the severity of the accident and the number of points assessed, rates can increase by as much as twenty to thirty percent.[21] Any motoring convictions should be disclosed to insurers, as the driver is assessed by risk from prior experiences while driving on the road.

Age

Teenage drivers who have no driving record will have higher car insurance premiums. However, young drivers are often offered discounts if they undertake further driver training on recognized courses, such as the Pass Plus scheme in the UK. In the US many insurers offer a good-grade discount to students with a good academic record and resident-student discounts to those who live away from home. Generally insurance premiums tend to become lower at the age of 25. Some insurance companies offer "stand alone" car insurance policies specifically for teenagers with lower premiums. By placing restrictions on teenagers' driving (forbidding driving after dark, or giving rides to other teens, for example), these companies effectively reduce their risk.[20]

Senior drivers are often eligible for retirement discounts, reflecting the lower average miles driven by this age group. However, rates may increase for senior drivers after age 65, due to increased risk associated with much older drivers. Typically, the increased risk for drivers over 65 years of age is associated with slower reflexes, reaction times, and being more injury-prone.