Improving compliance with medical fitness to drive reviews: The role of behaviourally-optimised letters

To manage the increased crash risk posed by drivers with medical conditions and impairments, many licensing authorities ask high-risk drivers to undergo medical fitness to drive assessments. Maximising drivers' compliance and satisfaction with these assessments is an ongoing challenge for these authorities. This study tested whether drivers' compliance and satisfaction with a licensing authority's request to provide a medical report could be improved by incorporating two applied behaviour change principles - simplified messaging and procedural fairness - into the authority's request letter. Drivers undergoing medical review (N = 876) were assigned to receive either a standard request letter currently used by the authority, or a revised letter that incorporated simplified messaging and procedural fairness amendments. Drivers who received the revised letter were significantly more likely to submit a medical report by the due date. Additionally, of the drivers who submitted the report, those who received the revised letter submitted the report an average of four days faster than those who received the standard letter. These findings demonstrate that optimising letters using behavioural principles can improve compliance with licensing authorities' requests, resulting in substantial time and cost savings for licensing authorities, possible road safety benefits, and potential reductions in the number of licences suspended for failure to provide a report.