Social cognitive determinants of offending drivers' speeding behaviour

The efficacy of an extended theory of planned behaviour (TPB) was tested in relation to offending drivers'(N= 1403) speeding behaviour. Postal questionnaires were issued at Time 1 to measure intention, instrumental and affective attitude, subjective and descriptive norm, self-efficacy, perceived controllability,moral norm, anticipated regret, self-identity, and past speeding behaviour. At Time 2 (6 months later),subsequent speeding behaviour was measured, again using self-completion postal questionnaires. The extended TPB accounted for 68% of the variation in intention and 51% of the variation in subsequent behaviour. The independent predictors of intention were instrumental attitude, affective attitude, self efficacy,moral norm, anticipated regret and past behaviour. The independent predictors of behaviour were intention, self-efficacy, anticipated regret and past behaviour. Theoretical and practical implications of the findings are discussed in relation to targeting road safety interventions.