City mobility patterns during the COVID-19 pandemic: analysis of a global natural experiment

Background

During the COVID-19 pandemic, changes were seen in city mobility patterns around the world, includingin active transportation (walking, cycling, micromobility, and public transit use), creating a unique opportunity forglobal public health lessons and action. We aimed to analyse a global natural experiment exploring city mobilitypatterns during the pandemic and how they related to the implementation of COVID-19-related policies.

Methods

We obtained data from Apple’s Mobility Trends Reports on city mobility indexes for 296 cities fromJan 13, 2020 to Feb 4, 2022. Mobility indexes represented the frequency of Apple Maps queries for driving, walking,and public transit journeys relative to a baseline value of 100 for the pre-pandemic period (defined as Jan 13, 2020).City mobility index trajectories were plotted with stratification by country income level, transportation-related citytype, population density, and COVID-19 pandemic severity (SARS-CoV-2 infection rate). We also synthesised globalpandemic policies and recovery actions that promoted or restricted city mobility and active transportation (walking,cycling and micromobility, and public transit) using the Shifting Streets dataset. Additionally, a natural experiment ona global scale evaluated the effects of new active transportation policies on walking and public transit use in citiesaround the world. We used multivariable regression with a difference-in-difference (DID) analysis to explore whetherthe implementation of walking or public transit promotion policies affected mobility indexes, comparing cities withand without implementation of these policies in the pre-intervention period (Jan 27 to April 12, 2020) and postintervention period (April 13 to June 28, 2020).