An Italian researcher measured the spatial distribution of pedestrians on sidewalks to determine how mask wearing affects how well people socially distance themselves from others. Massimo Marchiori, a computer scientist from the University of Padua, developed a sensor-based “social distancing belt” that was worn by researchers in Venice, Italy over a period of two months during the COVID-19 pandemic.
The sensor belt measured the distance that other pedestrians passed by the observers in both masked and unmasked situations. The sensors were turned off when in the presence of couples, parents with children, and people with dogs in order to only collect spatial data on single person to single person distancing. Three widths of sidewalks (163cm, 175cm and 222cm. ) located in high pedestrian traffic areas such as food shop locations were chosen. Sidewalks with a parallel green area or bike path were chosen to extend the allowable space a passerby could temporarily step out to. Five different types of masked/unmasked scenarios were measured: no masks, surgical masks, DIY masks (such as cloth masks), surgical masks with googles, and DIY masks with googles.
With over 12,000 encounters logged, Marchiori found that the use of masks was effective in increasing the amount of berth pedestrians gave the observers when passing by. Paradoxically, when no masks were worn, Marchiori found that pedestrians passed by with no extra space given. Despite warnings from the authorities about social distancing, the average social distance space provided to unmasked observers was only 29.4cm. When observers donned a surgical mask, the average social distance spaced nearly doubled to 58.42cm. DIY mask wearing netted a 69.02cm average social distance, surgical mask plus googles an average of 79.79cm, and DIY mask plus googles an average social distance of 92.39cm.
The results from Marchiori suggest that an added benefit of wearing masks when out walking in public is that it serves to promote better social distancing behavior among pedestrians.
Marchiori, M. (2020). COVID-19 and the Social Distancing Paradox: dangers and solutions. arXiv preprint arXiv:2005.12446. Retrieved from https://arxiv.org/pdf/2005.12446.pdf