Cognitive basis about risk level classifications for the self-assessment of older drivers

[Purpose] This study analyzed the cognitive functions according to risk level for the Driver 65 Plus measure, and examined the cognitive basis of self-assessment for screening the driving risk of elderly drivers. [Subjects and Methods] A total of 46 older drivers with a driver's license participated in this study. All participants were evaluated with Driver 65 Plus. They were classified into three groups of "safe," "caution" and "stop," and examined for cognitive functions with Trail Making Test and Montreal Cognitive Assessment-K. The cognitive test results of the three groups were compared. [Results] Trail Making Test-A, Trail Making Test-B, and Montreal Cognitive Assessment-K showed a significant difference between the three groups. The safe group showed significantly higher ability than the caution and stop groups in the three cognitive tests. In addition, cognitive functions of naming, attention, language, and delayed recall were significantly different between the three groups. [Conclusion] Self-assessment of older drivers is a useful tool for screening the cognitive aspects of driving risk. The cognitive functions, such as attention and recall, are the critical factors for screening the driving risk of elderly drivers.