Stress, violations and accidents.

Sources of stress among Western Australian car and truck drivers were investigated using an extended version of the Driver Behaviour Inventory (DBI) developed by Gulian et al (1989). The associations between reported stress and drivers' accident or violation records were also examined. The DBI was mailed to two groups each of 500 truck drivers with 'high' or 'low' traffic violation involvements and to two similar groups of car drivers, producing an overall response rate of 38%. Factor analyses related truck drivers' stress more to occupational demands and to 'imperturbability', whereas car drivers' stress was related more to psychological health, age, experience and aggression. Such factors predicted 30-40% of the variance in accident or violation reports.