Effects of theory of planned behaviour, identity and social identity constructs on motorcyclists' intentions to speed

Motorcyclists are over-represented in traffic crashes (Department for Transport, 2008) and research shows that the commission of speed violations significantly increases motor- cyclists crash risk (Horswill & Helman, 2003). This study therefore aimed to identify potentially modifiable cognitive variables that underpin motorcyclists speeding intentions (ie, variables that are likely to represent useful targets for safety interventions), using selected predictors from the theory of planned behaviour (affective attitude and perceived control-ability), identity theory (self-identity) and social identity theory (perceived in-group norm and group identification). Participants (N=110 motorcyclists) completed online questionnaire measures of all theoretical constructs, operationalised with respect to speeding on both 30 mph urban roads and 70 mph dual carriageways/motorways. The cognitive predictors together accounted for large amounts of variation in intentions to speed on both road types (in excess of 44%). The independent predictors of intentions to speed on 30 mph urban roads were affective attitude and perceived controllability. For 70 mph roads, the independent predictors of speeding intentions were affective attitude and each identity construct. Additionally, and in line with social identity theory, it was found that the effect of perceived in-group norm on intention increased with group identification. The findings demonstrate that the cognitive variables examined in this study together constitute a useful model for predicting motorcyclists speeding intentions. They also demonstrate that interventions (eg, road safety education) need to be carefully targeted at the different predictors of intentions to speed on different road types