Promoting drivers' compliance with speed limits: testing an intervention based on the theory of planned behaviour.

The efficacy of a theory of planned behaviour (TPB)-based intervention to promote drivers' compliance with speed limits was tested. Participants (N=300) were randomly assigned to an experimental condition, and received persuasive messages designed to change beliefs as specified in the TPB, or a control condition. Baseline and follow-up (1 month post-baseline) measures of TPB variables and behaviour were collected using postal questionnaires. Results showed that the intervention had a significant effect on one control belief, and significantly increased perceived behavioural control and reported behaviour. Mediation analyses confirmed that the control belief change generated the perceived behavioural control change and that the perceived behavioural control change generated the behaviour change. Implications for promoting road safety are discussed.