Introduction: In Japan, the rate of car accidents involving older drivers is increasing compared to younger and middle-aged drivers. Therefore, preventing car accidents is a critical issue in super-aged societies such as Japan.
Objectives: This study aimed to investigate the relationships between driving ability, assessed using a driving simulator, and physical and cognitive functions in older drivers.
Methods: Twenty older drivers (aged ≥65 years) who drove regularly participated in this study (mean age: 77.5 ± 5.7 years; 5 men, 15 women). Driving ability was evaluated using a driving simulator, assessing both steering and accelerator-brake pedal operation. Physical function was measured using gait speed, the Timed Up and Go test, the Chair Stand test, grip strength, knee extension strength, and toe-grip strength. Cognitive function was assessed using the Montreal Cognitive Assessment (MoCA) and the Trail Making Test (TMT). The relationships between driving ability and physical and cognitive functions were analyzed statistically. Written informed consent was obtained from all participants, and the study protocol was approved by the institutional review board (2024-009).
Results: Steering ability was significantly associated with knee extension strength and toe-grip strength. Additionally, accelerator-brake pedal operation ability was significantly correlated with MoCA and TMT scores.
Conclusion: Driving ability in older drivers appears to be influenced by both physical function, particularly lower limb muscle strength, and cognitive function. Maintaining and improving these functions may help preserve driving ability and reduce the risk of motor vehicle crashes.