At the most basic level, initial ratemaking involves looking at the frequency and severity of insured perils and the expected average payout resulting from these perils. Thereafter an insurance company will collect historical loss data, bring the loss data to present value, and compare these prior losses to the premium collected in order to assess rate adequacy. Loss ratios and expense loads are also used. Rating for different risk characteristics involves at the most basic level comparing the losses with "loss relativities"—a policy with twice as many losses would therefore be charged twice as much. More complex multivariate analyses are sometimes used when multiple characteristics are involved and a univariate analysis could produce confounded results. Other statistical methods may be used in assessing the probability of future losses.
Naturally, insurance companies use your driving past as an indicator of how you will drive in the future. It can be difficult to find affordable car insurance if you have a checkered driving history. While it’s very unlikely you will find an insurance company that won’t increase your premium after an at-fault accident or other violation, the degree of the rate increase will vary by company. Let’s compare rate increases for some common violations across major insurance companies.
The above is meant as general information and as general policy descriptions to help you understand the different types of coverages. These descriptions do not refer to any specific contract of insurance and they do not modify any definitions, exclusions or any other provision expressly stated in any contracts of insurance. We encourage you to speak to your insurance representative and to read your policy contract to fully understand your coverages.