Fig. 2

Stringency index from Oxford University (green) [30] and the relative change in the number of visitors to transit stations (red) compared to the baseline period (January 3 - February 6), based on Google mobility data [27]. Full color refers to period with CoMix data collection while lighter color refers to out of CoMix data collection. Holiday periods are depicted in the shaded areas. Black lines depict the periods corresponding to the different CoMix waves [12, 26]