Figure 9

Histogram of density-speed tuples. Histogram of the density-velocity relation of our data set the kernel radii (a)$R=10\text{ m}$ and (b)$R=55\text{ m}$, respectively. The plots depict a two-dimensional histogram of all obtained density-velocity tuples (logarithmic scale). The color values indicate the occurrence frequency of a tuple. It is observable that the walking velocity covers the whole range from $0{\text{ ms}}^{-1}$ up to a maximal value for a given density. This upper limit is depends on the crowd density and decays for larger crowd densities.