Gender–age inequalities in public service facility demand: Spatiotemporal evidence from Tokyo

High-density megacities face growing challenges in equitably organizing public service facilities (PSFs) to meet heterogeneous demands across population groups. However, comprehensive evidence on how gender–age differences interact with weekday–weekend contexts to reshape PSF demand and inequality remains limited. This study addresses this gap by using mobile phone location data to trace daily travel behavior of 10 gender–age cohorts in Tokyo's 23 special wards in May 2023. Based on visit event identification and aggregation into 250 m × 250 m grids, we introduced a Visiting Preference Index to quantify group-level functional demand across seven PSF categories and evaluated inter-group inequality and temporal stability using a grid-level relative demand indicator (RDI). Three main findings emerged: (1) Clear group-differentiated temporal preference shifts were observed: transportation and restaurant activities showed the strongest weekend amplification, whereas education remained strongly weekday-oriented. (2) Functional preference intensity was only weakly associated with grid-level spatial demand (RDI) (R 2 = 0.251, p < 0.001), suggesting that urban spatial structures mediate activity preferences into uneven realized demand patterns. (3) Inter-group inequality intensified on weekends: mean Gini coefficients increased from 0.252 to 0.291 (Δ ≈ 15%), while dispersion structures remained highly stable, indicating persistent spatial hierarchies despite declining weekend demand. These results revealed non-intuitive dynamics in which temporal changes amplified rather than reconfigured existing spatial inequalities. These findings highlight how demographic structure and temporal rhythms jointly reshape urban service demand and support differentiated PSF planning strategies combining facility redistribution with mobility-enhancing interventions. • Gender–age groups show weekday-weekend shifts, strongest in youth and mid-life cohorts. • Weak LQ – R D I coupling (R 2 = 0.251) reveals systematic preference–demand decoupling. • Inter-group inequality rises on weekends (Gini: 0.252 .→ 0.291, +15%) despite reduced demand • Spatial demand patterns remain stable, with temporal dynamics amplifying existing inequalities. • The VPI–LQ– R D I framework links preferences to spatial outcomes at fine scales.