Predicting motorcyclists' intentions to speed: effects of selected cognitions from the theory of planned behaviour, self-identity and social identity.

This study sought to identify cognitive predictors of motorcyclists' intentions to speed using a model that comprised selected constructs from the theory of planned behaviour (TPB), supplemented with constructs from identity theory and social identity theory. Participants (N=110) were sampled from motorcycle clubs in Scotland and they completed web-based questionnaire measures of all cognitive variables, operationalized with respect to speeding on both 30 mph urban roads and 70 mph dual carriageways and motorways. In support of the TPB element of the model, affective attitude and perceived controllability accounted for significant variance in intention to speed on each road type. The identity constructs accounted for additional variance in intentions to speed on 70 mph roads. The significant independent predictors of speeding intentions on 30 mph roads were affective attitude and perceived controllability. For 70 mph roads, the independent predictors of intention were affective attitude, self-identity, perceived group norm, group identification, and an interaction between perceived group norm and group identification. Consistent with predictions derived from social identity theory, decomposition of the interaction showed that perceived group norm had an increasing effect on intention with increases in group identification. Implications for theory development and safety interventions are discussed.