Examining the effects of road safety advertising that encourages positive, prosocial driving behaviours

• Investigated road safety advertising for prosocial driving in general and the specific behaviours of slowing down and considering others. • Robust study methodology underpinned by Step approach to Message Design and Testing (SatMDT). • Some support found for the effectiveness of prosocial driving advertisements with two of the four ads improving intentions after viewing. • Regressions found the ads may have increased individuals' preceptions of behavioural control and morality (moral norms) of prosocial driving. Prosocial driving behaviours are performed to benefit other road users and without legal obligation. This online survey study, guided by the Step approach to Message Design and Testing (SatMDT), examined advertisements in terms of drivers’ intentions and willingness to drive in a prosocial way. ‘Drive in a prosocial way’ was operationalised in both general and specific terms. N = 213 participants (48.8 % female; M = 54.0 years, SD = 15.1 years) were randomly allocated into four intervention groups (i.e., Advertisement 1, 2, 3, or 4) or a control group. Overall, in the intervention groups, while relatively high mean scores were found, one-way ANOVAs revealed there were no statistically significant differences between the advertisements. Reverse third person effects were found for all the advertisements suggesting participants perceived they would be influenced by them more than others. Regarding between groups comparisons, intentions and willingness scores increased (i.e., became more positive towards prosocial driving) after having viewed an advertisement; however, paired samples t tests indicated these differences were only statistically significant for general and specific intentions after viewing Advertisement 2, and for specific intentions after viewing Advertisement 4. To understand how the advertisements were influencing individuals’ intentions, regressions were conducted which found 72 % − 90 % of variance was explained by the variables of attitude, subjective norm, perceived behavioural control [PBC], moral norms, and anticipated regret. PBC and moral norms were significant predictors for three of the advertisements. Overall, this study supports the need for further research into messaging promoting prosocial driving behaviour.