Intervention
The All participants (irrespective of group allocation) received smartcard credit as study compensation. Compensation was commensurate with participation and independent of incentive scheme: completion of the baseline assessment (T1) = $5 credit and completion of the post-intervention follow-up assessment (T2) = $10 credit [The intervention used a ‘gain-framed’ approach which rewards positive behaviours. Participants were set weekly bus trip targets from weeks 1–16 and, if intervention group participants met their target number of bus trips, bus trip credit (financial incentive) was issued to their smartcard. The number of target trips increased over time; with this escalation, financial incentives also increased (Additional file Participants were set a target of five one-way bus trips per week by the end of the intervention phase. The credit (incentive) received was equal to the value of the weekly trip target (adjusted to the participant’s usual fare type) [Both the intervention and control groups received printed versions of the Australian Physical Activity and Sedentary Behaviour Guidelines [