Understanding bias in older drivers’ self-reported driving styles using naturalistic driving data

OBJECTIVE: Accurate self-assessment of driving performance is critical for maintaining safety and mobility among older adults. However, many older drivers exhibit discrepancies between perceived and actual driving performance, which may lead either to unsafe driving in cases of overestimation or to premature driving cessation in cases of underestimation. This study aimed to examine the consistency between self-rated driving styles and objectively measured driving performance among older drivers, to identify drivers who overestimate or underestimate their performance, and to explore the factors associated with inaccurate self-assessments. METHODS: Naturalistic driving data were obtained from 58 older drivers aged 65 years and above who participated in the Data Repository for Human Life-Driving Anatomy project. The rate of harsh events-including sudden starts, braking, and steering-was computed as an objective indicator of risky driving behavior. Self-reported driving styles were assessed using the Driving Style Questionnaire, which measures several dimensions of perceived driving behavior including careful, risky, and anxious driving styles. An unsupervised machine learning method was developed to identify drivers who overestimated or underestimated their driving behaviors. Logistic regression models were then estimated to examine the associations between inaccurate self-assessment and explanatory variables such as age, gender, driving confidence, and personality traits. RESULTS: Weak correlations were found between self-reported driving styles and objectively measured performance, indicating inconsistencies between perceived and real-world behaviors. Self-confidence in driving ability and personality traits were significant predictors of inaccurate self-assessments. Over-estimators showed higher self-reported confidence, whereas under-estimators exhibited lower confidence. Impulsive drivers were more likely to overestimate their performance, while both sensation seeking and impulsivity were negatively associated with underestimation. Moreover, older age was linked to a greater likelihood of overestimation. CONCLUSIONS: These findings suggest that caution is warranted when relying on self-report data to assess older drivers' driving performance, and that the anxious driving style score, which reflects confidence in driving ability, may serve as a useful tool for identifying older drivers with inaccurate self-assessments of their driving behavior. Insights from this study can inform the development of tailored intervention strategies that enhance both road safety and sustained mobility among older adults.