Intentional Travel Groups and Social Networks during the COVID-19 Pandemic

Abstract

Although face-to-face social contacts decreased during the COVID-19 pandemic, some people remain physically traveling and meeting as a group to gain benefits like sustaining intimacy and increasing productivity. Using multiday continuous smartcard data, we identify intentional group travel patterns in Hong Kong Metro system. Those patterns serve as our proxies for physical (visible) interactions and social (invisible) contact networks among people who intentionally travel as a group (ITGs). We measure the spatial centrality of ITGs and persistent group riders (PGRs), a subset of ITGs remaining active amid the pandemic, to infer different locales' social interactions in the city. By examining the social network formed by ITGs across time, we found that its size and interconnections varied during the pandemic and PGRs might be the most influential vertices in maintaining the networks’ topological properties. The findings could facilitate transit-usage-and-virus-spread modelling and the formulation of more effective pandemic countermeasures in transit-reliant cities.