Does age matter? Examining age-dependent differences in at-fault collisions after attending a refresher course for older drivers

•The effect of a voluntary refresher course for elderly drivers on motor vehicle collisions (MVC) was estimated.•Drivers who attended the course before 75 years of age had lower odds of being at-fault in multi MVCs.•Indications of higher odds of single MVC and at-fault multi MVC was found for course participants at the age of 75 years or more.•A possible explanation is that a certain level of functioning is needed to implement the strategies learned in the course.•The design of the study makes it difficult to determine the causal relationship between course attendance and MVC's.