Study timeline
Each participant will be involved in the trial for a total of 28 weeks, consisting of a 4-week baseline period, 20-week post-randomisation (intervention) period, and 4-week post-intervention period. To join the trial, a participant will sign a consent form and complete a pre-trial questionnaire. Upon consent and completion of the pre-trail questionnaire participants will receive a link via SMS to download the FEEDBACK app. Once a participant downloads the FEEDBACK app and pairs the smartphone with their car (via Bluetooth), their participation in the trial will commence.During the 4-week baseline period, the FEEDBACK app will collect data on the participant’s driving behaviours: speeding, braking, and acceleration. However, the app will not display any information to the participants during the baseline period (see Fig. 