Fig 1.
Analysis framework.
Table 1.
The eight policy restriction phases.
Fig 2.
The mobile phone GPS trajectory sample and urban characteristic distribution at OA-level in Greater London.
Map A shows a sample user’s GPS trajectory without the start and end points; Map B shows the distribution of OAs’ land use in ten types (we plot each OA in one land use represented by the maximum land use acreage in ten types). Map C shows the eight supergroups of OA socio-demographic classification. (Geographical boundary data source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2022. Contains National Statistics data © Crown copyright and database right 2022.).
Fig 3.
Daily footfall recovery index in Greater London from 2020-01-01 to 2021-02-07.
Daily and 7-day rolling window observations are shown as light blue and dark blue lines, respectively. The eight policy restriction phases are distinctively separated by vertical lines labelled with the start/end date.
Fig 4.
The colour palette used in HAZ delineation maps.
Fig 5.
HAZs (top) and corresponding footfall patterns (bottom) of Greater London during all observation periods.
The HAZs are ranked by the daily average footfall volumes from high level to low level. The temporal footfall variations for each HAZ are represented by the mean of all related OAs’ footfalls. (Geographical boundary data source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2022. Contains National Statistics data © Crown copyright and database right 2022.).
Fig 6.
HAZs of Greater London in eight distinctive policy restriction phases.
For each phase, the HAZs are extracted from footfall patterns, and the HAZ numbers are 6, 7, 7, 8, 6, 5, 5, 5, respectively. The vertical lines in the temporal footfall figures denote weekends. (Geographical boundary data source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2022. Contains National Statistics data © Crown copyright and database right 2022.).
Table 2.
The Daily average footfall volumes and OA numbers of HAZs in eight policy restriction phases.
Fig 7.
The difference between the HAZs from eight restriction phases.
Fig 8.
The accuracy values (left) and feature importance values of urban characteristics (right) in RF classifiers of different restriction phases.
There are ‘Before lockdown’ (Classifier 0), ‘First national lockdown’ (Classifier 1), ‘Minimal lockdown restrictions’ (Classifier 2), ‘Reimposing restrictions’ (Classifier 3), ‘Three-tire restrictions’ (Classifier 4), ‘Second national lockdown’ (Classifier 5), ‘Four-tier restrictions’ (Classifier 6), and ‘Third national lockdown’ (Classifier 7).
Fig 9.
The HAZs within the urban centre’s buffer area (6 km) in the before lockdown phase and the second national lockdown phase.
Geographical boundary data source: Office for National Statistics licensed under the Open Government Licence v.3.0. Contains OS data © Crown copyright and database right 2022. Contains National Statistics data © Crown copyright and database right 2022.