Personalised financial incentives
DrivePoints
Financial incentives will be structured as penalties for risky driving; levied as monthly deductions from an upfront payment of AU$120 deposited to a virtual ‘safe driving account’. This approach is designed to mimic a PAYD implementation, where financial penalties are typically framed as periodic deductions from an (earned) discount on PAYD insurance premiums. If a participant fails to meet their safe driving target for a given month, AU$24 will be deducted from their safe driving account that month. Participants will receive no penalty for risky driving provided that their driving behaviour remains consistent with achievement of their safe driving target (e.g., yellow and amber DriveScores would not incur a penalty if the monthly safe driving target is no more than one red DriveScore). Each week, the intervention group participants will receive an SMS updating them on the weekly draw, their current DrivePoints score and safe driving target, and safe driving account balance (see Table 
An example SMS message a participant in the intervention group receives during the intervention periodAfter the 20-week intervention period, there will be a 4-week post-intervention period. During this time, participants will not be entered into weekly draws. The intervention group will also not be able to view information in the FEEDBACK app, nor receive SMS messages with updates on their DrivePoints scores, safe driving targets, or safe driving account balance. However, they will receive an SMS message reminding them to keep location tracking enabled for the FEEDBACK app. Mortimer et al.’s [At the end of this post-intervention period, participants will receive a link to the post-trial questionnaire. Upon completing the questionnaire, the control group will be entered into one final draw. The intervention group will be able to receive the remaining funds of their safe driving accounts via an e-voucher. Figure 
An overview of the FEEDBACK Trial illustrating the activities during each stage of the trial: 4-week baseline, 20-week post-randomisation (intervention) and 4-week post-intervention periodParticipants can withdraw from the trial at any time but will not receive financial compensation thereafter. To withdraw, a participant can contact one of the trial coordinators via email. If a participant does not inform the trial coordinators of their withdrawal but the research team no longer receives telematics data from a participant, a research staff member will call the participant to confirm whether the participant has removed the FEEDBACK app or disabled location services and whether they still intend to participate in the trial.