Mobility restrictions as a pandemic response

The COVID19 pandemic has caused a large number of infections and fatalities, causing administrations at various levels to use different policy measures to reduce viral spread by limiting public mobility. This paper analyzes the complex association between the stringency of restrictions, public mobility, and reproduction rate (R-value) on a national level for Germany. The goals were to analyze; a) the correlation between government restrictions and public mobility and b) the association between public mobilities and virus reproduction. In addition to correlations, a Gaussian Process Regression Technique is used to fit the interaction between mobility and R-value. The main findings are that: (i) Government restrictions has a high association with reduced public mobilities, especially for non-food stores and public transport, (ii) Out of six measured public mobilities, retail, recreation, and transit station activities have the most significant impact on COVID19 reproduction rates. (iii) A mobility reduction of 30% is required to have a critical negative impact on case number dynamics, preventing further spread.