Out of the simulations, it appears that social distancing plays less of a role for 2 people in a low wind environment when running/walking next to each other. The droplets land behind the duo. When you are positioned diagonally behind each other the risk is also smaller to catch the droplets of the lead runner.
On the basis of these results the scientist advises that for walking the distance of people moving in the same direction in 1 line should be at least 4–5 meter, for running and slow biking it should be 10 meters and for hard biking at least 20 meters. Also, when passing someone it is advised to already be in different lane at a considerable distance e.g. 20 meters for biking.
