  In urban transportation systems, mobility flows in the subway system reflect
the spatial and temporal dynamics of working days. To investigate the
variability of mobility flows, we analyse the spatial community through a
series of snapshots of subway stations over sequential periods. Using Shanghai
as a case study, we find that the spatial community snapshots reveal dynamic
passenger activities. Adopting a dual-perspective, we apply spatial and
temporal models separately to explore where and when individuals travel for
entertainment. In the two models, microblog topics and spatial facilities such
as food venues and entertainment businesses are used to characterise the
spatial popularity of each station and people's travelling perceptions. In the
studied case, the city centre is characterised by greater social influence, and
it is better described by the spatial model. In the temporal model, shorter
travel distances motivate individuals to start their trips earlier.
Interestingly, as the number of food-related facilities near the starting
station increases, until it exceeds 1563, the speed of people's journeys slows
down. This study provides a method for modelling the effects of social features
on mobility flows and for predicting the spatial-temporal mobility flows of
newly built subway stations.
