Differentiating risky and aggressive driving: further support of the internal validity of the Dula Dangerous Driving Index.

The Dula Dangerous Driving Index (DDDI) is a cross-cultural validated instrument that measures simultaneously various manifestations of behaviours, cognitions, and affects associated with dangerous driving. The aims of the study were to translate the DDDI into French and then to verify the validity and reliability of the French version of the scale by means of observed behaviours on a driving simulator, and of self-reported measures of driving behaviours, personality and sociodemographic characteristics. A first sample of 395 drivers completed self-reported questionnaires and a second sample of 75 male drivers also completed tasks on a driving simulator. A confirmatory factorial analysis supported the internal validity of the scale. Findings also show that the French version of the DDDI yields good internal consistency, concomitant and convergent validity for each subscale (risky driving, negative cognitive/emotional driving and aggressive driving) and total score. The scale was useful to differentiate sociodemographic and psychological profiles associated with each subscale.