What does how far I drive to work each day have to do with my auto insurance rate?

In NC, the personal auto policy has several different rate classifications for the use of the cars. In order of lowest cost to highest cost they are as follows. There is a farm rate for vehicles primarily used on a farm, then a pleasure rate for those vehicles not driven to work. Next is a classification for vehicle that are driven to work but less than 10 miles one way. After that is the rate for vehicles driven to work but more than 10 miles one way. The most expensive classification is for vehicles used in business.