An interesting article published in PLOS1 March 15th 2021 by Hoben and others reviewed this question.
They analysed CCTV clips to assess people’s behaviour in public spaces.
They concluded that compliance with social distancing directives appeared to decline in the weeks after initial implementation.
They further established strong correlations between, on the one hand, the number of observed physical distancing violations and, on the other hand, the number of people on the street and community wide mobility.
The findings implied that directives about keeping distance may work best in combination with stay at home directives and specific crowd control strategies and as such, policymakers should not rely on people keeping 1.5 or 2 m distance from others in public whilst allowing for relaxation of stay at home directives.
The findings also implied that indicators of community wide mobility and of the number of people on the street might be used as proxies to assess whether people keep sufficient physical distance from each other at specific times and locations.
Dr Paul Ettlinger
BM, DRCOG, FRCGP, FRIPH, DOccMed