Gamification as technological innovation in sustainable urban mobility: evidence from a digital field experiment

• We combine descriptive statistics and econometrics to empirically estimate the effect of incentive scheme design in sustainable mobility gamification programs. • We find that individual-rewards-based schemes produce the most stable and widespread participation while solidarity-based schemes are associated with fewer and shorter trips. • We hypothesize that individual rewards nudge utilitarian behavior translating into high-frequency and long-distance trips, while donation-based incentives nudge prosocial or symbolic engagement without necessarily maximizing effort or frequency. • We extend the mobility gamification literature by focusing on the scheme design effect, beyond the single-scheme, pre vs post introduction analyses. • Policymakers may consider both schemes, recognizing that utilitarian rewards sustain broader engagement, while solidarity-based incentives appeal to specific motivational segments but are likely to generate lower overall engagement. Digital and gamified tools are increasingly used to support sustainable urban mobility policies by influencing individual travel behaviour. This study analyses how three gamified incentive schemes, Inclusive, Competitive and Solidarity-based, affect sustainable mobility behaviour in a real-world context. The analysis draws on a randomized field experiment carried out in three mid-sized cities in Apulia, Southern Italy, involving 195 participants and 12,381 digitally tracked trips collected through an app and IoT devices. Results indicate that the individual reward schemes (Inclusive and Competitive) support the most stable and widespread participation, while the Solidarity-based scheme, which converts rewards into charitable donations, leads to fewer and shorter trips. The findings suggest that gamification can complement digital mobility policies by supporting motivation for sustainable travel engagement. Inclusive and performance-based designs seem to sustain participation more effectively, while solidarity incentives, although better suited for awareness and community-oriented purposes, would likely yield lower participation compared with other incentive schemes.