Individual Differences In Driver Over-Confidence: Implications For Stress, Error And Managing Impairments

This study aimed to extend understanding of individual differences in over-confidence in driver safety. First, we discriminated general driving confidence from confidence in coping with impairments such as fatigue and distraction. Second, we discriminated three aspects of overconfidence specified in terms of a recent Bayesian belief updating model of over-confidence (Moore and Healy, 2008): overestimation, overplacement and overprecision. Calibration tasks were used for this purpose. Results showed that the magnitude of overconfidence differed across the various metrics, and different metrics were only modestly intercorrelated. Confidence in handling impairment appears to be distinct from general confidence. Both forms of confidence were negatively related to dislike of driving but related differently to other aspects of driver behavior and stress. Risk factors related to self-estimation (violations, thrill-seeking) may be distinct from factors related to overplacement (aggression). Discrimination of multiple metrics for driving overconfidence may support better matching of safety interventions to the individual driver