Fig 3.

(a, b) Radial cumulative distribution functions (RCDF), g(r), and (c, d) radial distribution functions (RDF), G(r), for density levels on a typical working day. On the left (a, c) for density level 1, with 40-50 pedestrians on the platform, (green domain in Fig 2) and on the right (b, d) for density level 2, with 70-80 pedestrians on the platform (purple domain in Fig 2). Vertical dashed lines at 1.5m, 2.2m and 2.5m indicate, respectively, the Dutch social distancing regulations (r < D), the usable width of the platform (without danger zone) and the critical threshold D′. The solid black line at small r values highlights the ∼r² growth ratio up to 2.2 m and a blue line for the ∼r¹ trend at larger mutual distances. In (b,d) the normalization constant c is chosen such that ${\int }_0^{\infty }cg\left(z\right)dz=N$, where N is the number of people on the platform. Similar plots for a weekend day are reported in Fig 6. We compare the pre-Covid situation with the present, and with a Monte Carlo model of a random distribution of passengers across a region identical to the platform. We report the RDF and RCDF of the current situation including and excluding family-groups contributions, as made possible by the method introduced in Section 5.