Quantification of latent travel demand across age groups with a focus on older adults: a theoretical framework with empirical evidence from China

Against the backdrop of global population aging, promoting mobility among older adults is essential for achieving active aging goals. Drawing on the latent travel demand perspective, this study develops and validates a four-dimensional framework—health barriers, functional capacity, social participation, and technology acceptance—to identify and quantify latent travel demand across age groups, with a focus on older adults. Age-stratified regression analyses were conducted using 664 survey samples from Ningbo, China. The results show that social participation is the strongest and most stable predictor of latent travel demand across the 35–59, 60–74, and 75+ age groups. It contributes 75.3% of total latent travel demand and 86.6% of active travel latent demand, with each standard deviation increase associated with approximately 1.2–1.5 additional daily total trips and 0.6 additional active trips. The disaggregated analysis shows that social interaction is the strongest driving component of the Social Participation Index. In contrast, health barriers and functional capacity display distinct age-specific patterns: health barriers primarily reduce total trips in the 35–59 group by approximately 0.25 per standard deviation increase, whereas functional capacity exerts a stronger positive effect among adults aged 75+, adding approximately 0.6 daily trips per standard deviation improvement. Technology acceptance shows no significant effects across groups. The findings suggest that age-friendly policy should move beyond physical infrastructure improvement alone and place greater emphasis on promoting social participation. In Ningbo, policy priorities may include expanding senior universities and community activity centers, promoting neighborhood and community activities, developing flexible employment and volunteering opportunities, and providing assisted transportation services for adults aged 75 and above. Beyond the Ningbo case, the framework can be adapted to local contexts and integrated with end-point evaluation tools to support systematic assessment of age-friendly mobility policies.