Development and evaluation of a mass media Theory of Planned Behaviour intervention to reduce speeding.

The Theory of Planned Behaviour (TPB) has been widely applied to the explanation of health and social behaviours. However, despite its potential to inform behaviour change efforts, there have been surprisingly few attempts to use the TPB to design actual interventions. In 1998, the Scottish Road Safety Campaign implemented a 3-year mass media campaign to reduce speeding on Scotland's roads which was explicitly shaped by the TPB's three main predictors: Attitude, Subjective Norms and Perceived Behavioural Control. A 4-year longitudinal cohort study examined the impact of the campaign on communications outcomes and on TPB constructs. Overall, empirical support was found for the decision to use TPB as the theoretical underpinning of the advertising. The advertising was effective in triggering desired communications outcomes, and was associated with significant changes in attitudes and affective beliefs about speeding. In conclusion, future directions for road safety advertising and for TPB research are discussed.