Non-linear impacts of COVID-19 pandemic on human mobility: Lessons from its variations across three pandemic waves

Abstract

This study sought to understand how the COVID-19 pandemic influenced human mobility patterns in a city, how the influences varied across the pandemic wave phases, and how the influences differed between car and bus trips. Data for the pandemic and individual-level trips were collected from Daejeon Metropolitan City in South Korea. Three indices of trip demand and trip randomness were used to represent mobility patterns and were compared with the number of confirmed COVID-19 cases. The results demonstrated different responses to the pandemic by transportation mode and revealed non-linear impacts of the COVID-19 pandemic on mobility patterns. Car dependency intensified and car trip randomness more sensitively fluctuated as the pandemic spread. The COVID-19 impacts on mobility follow a power-law relationship that revealed the existence of lower bounds of citizens' travel-related responses to the pandemic, which generally increased over time, but its trend differed according to trip demand and randomness as the pandemic continued. The findings demonstrate variations in mobility patterns due to the long-lasting pandemic, which could not be explained solely by trip demand. This information can assist in the formulation of flexible policies that adapt to changes in travel behaviors.