Mobility Data Analysis and Application in the United Kingdom

The work discussed in this blog was presented to the COVID-19 Mobility Data Network on August 14, 2020, as part of regular weekly meetings that aim to share information, analytic tools, and best practices across the network of researchers.

The MRC Centre for Global Infectious Disease Analysis (MRC GIDA) at Imperial College London is an international resource and centre of excellence for research and capacity building on the epidemiological analysis and modelling of infectious diseases, and to undertake applied collaborative work with national and international agencies to support policy planning and response operations against infectious disease threats. Caroline Walters details how the researchers at the Centre leveraged crowd level mobility data to assess compliance with social distancing measures across populations in the United Kingdom. Using anonymized data from the Facebook Data for Good program, the research team calculated the daily percentage change from baseline in the number of trips starting from within each UK local authority district. The analysis was repeated on a separate dataset from a mobile phone operator.

They found that the two mobility datasets produced similar trends, showing that mobility began to decrease around one week before UK lockdown was enforced on March 24, 2020 and that there was little variation in trend across the 4 countries (see figures 1 and 2). They also found that there were larger reductions and greater variation in mobility in high population density areas relative to low population density areas. After the sharp decrease immediately following the lockdown, they observed a gradual and continuing increase in mobility across the UK.

Figure 1: Change in movement over time as a percentage of baseline movement for the four home countries within the UK and their largest city for Facebook data (blue) and mobile phone data (red)

Figure 2: Reduction in mobility from March 18-26, 2020 relative to the baseline

The research team is currently working with the UK Government by monitoring mobility data trends in local outbreak areas and sending weekly .csv data files to aid both other researchers and policy makers in the COVID-19 response. Their manuscript is available here, with additional information on their data sources, and the code used to run the discussed analyses and plot the figures are made available through Github.