Do reward-based incentives via smartphones encourage modal shift to sustainable modes?

A recent approach to mitigating the negative externalities of transport is to use information technologies to encourage more sustainable travel choices. However, evidence of their effectiveness is limited. Our study examines the impact of point-based incentives offered through a mobile app that encourages users to cycle, walk, and use public transport by offering redeemable points. Using a discrete choice modelling approach and track-and-trace data, the results showed that users increased the likelihood of switching from cars to sustainable modes by over 15%. Incentives offered on the same day as the car trip had the strongest effect. Public transport and cycling rewards were effective when sent up to 3 days before the car trip, while walking rewards were effective when sent up to 2 days before. Our study also highlights the influence of trip distance, inertia, trip purpose, and day type on travellers’ switching behaviour.