Figure 4

Schematic diagram for multiple gravity laws in a centralized urban landscape. The dark shaded circle at the center and the bright shaded ring at the periphery denote groups of \(k=1\) and \(k=10\), respectively. Distance exponents \(\gamma _{10,10}\), \(\gamma _{1,1}\), and \(\gamma _{1,10}\) characterize the distance dependence of traffic volumes between or within groups. Arrows visualize some possible trips between or within groups