Mobility models predictions. These 2D-histograms compare the predicted values against the real flow values for (A), (C) the gravity model; (B), (D) the hybrid model. Each point represents flows with some real/estimated flow value relation. Points color in a gray scale represents the frequency values. The boxplots correspond to the interquartile range within a bin. (A), (B): US Commuting network. (C), (D): US air travel network.