Figure 13

Testing the modified gravity law with GDP for the directed and undirected freight highway transportation networks constructed over five months. (a) Scatter plot of \(F_{ij}\) with respect to \(G_{i}^{\alpha_{1}}G_{j}^{\alpha_{2}}/d_{ij}^{\alpha_{3}}\) for the directed network. (b) Binning plot of \(F_{ij}\) with respect to \(G_{i}^{\alpha _{1}}G_{j}^{\alpha_{2}}/d_{ij}^{\alpha_{3}}\) for the directed network. (c) Scatter plot of \(W_{ij}\) with respect to \(G_{i}^{\alpha_{1}}G_{j}^{\alpha _{2}}/d_{ij}^{\alpha_{3}}\) for the undirected network. (d) Binning plot of \(W_{ij}\) with respect to \(G_{i}^{\alpha_{1}}G_{j}^{\alpha_{2}}/d_{ij}^{\alpha _{3}}\) for the undirected network