For most insurance companies, a student that is going to school more than 100 miles from home, can have their coverage suspended while away at school. When doing so, you are responsible to make sure they are added back on after they return. Under that 100 mile radius, companies require they still be listed as a potential driver. It has been shown that students within that radius more commonly come home for weekends and drive the car. Parents are more likely to allow the student to take the car back to school for a week intermittently.