Interventions to facilitate long-term travel data collection via smartphones

• Tested interventions to motivate engagement with a cycling app for more complete trip chain recording. • Measured trip chain completeness via spatio-temporal continuity of GPS data. • Continuous economic incentives improved trip recording across genders, ages, and cycling frequency. • Gamified challenges and trophies were partly effective, with differences across genders and cycling frequencies. • Nudging messages were ineffective overall and even reduced trip recording in some subgroups. Smartphone applications used in travel surveys can increasingly detect trip characteristics automatically. However, manual validation and labeling remain necessary, often leading to incomplete data and participant attrition. Continuous incentives − small, frequent rewards for ongoing participation − may improve data completeness by sustaining respondent motivation and engagement. This study examined the effects of economic, gamification, and nudging interventions on the completeness of GPS-based cycling data collected via a mobile app. Three separate time periods with different reward structures were compared: 1) low monetary rewards, 2) high monetary rewards, and 3) gamification elements with nudging applied to a random subset of the sample. Completeness was evaluated using two outcomes: (1) overall trip recording rate and (2) the rate of spatially unchained trips − pairs of recorded trips whose start and end locations did not match, indicating at least one unrecorded trip. Andersen–Gill survival models estimated the change in each outcome during the interventions, adjusting for demographic and behavioral factors. The results indicate that the period with higher economic rewards simultaneously increased the trip recording rate and reduced the rate of unchained trips, indicating improved data completeness as compared to the period with low economic rewards. Gamification significantly reduced the rate of unchained trips but did not increase overall trip recording as compared to the period without gamification, providing only partial evidence of its effectiveness. Nudging had no significant effect on either outcome. These findings contribute to travel behavior research by demonstrating how travel data collection efforts can be improved to incentivize respondent engagement. These findings contribute to travel behavior research by showing how different incentive strategies can improve participant engagement in travel data collection. Methodologically, the study introduces a spatially based approach for assessing the continuity and completeness of GPS-derived travel data.