We use Monday as a case study to show the distribution of traffic volume and average speed in the road network. (a) shows the distribution of traffic volume in the road network, the X-axis represents the traffic volume, the Y-axis represents the percentage of roads which volume equal x. (b) shows the distribution of average speed in the road network, the X-axis represents the average speed (km/h), the Y-axis represents the percentage of roads which average speed equal x. (c) shows the degree distribution of the bus-layer in Britain and the two-layer UTN in Changchun. In reference22, the edge weights are defined as either the minimal travel time or Euclidean distance. To make consistence with this study in Changchun, we take the bus stations as nodes and the bus lines as edges weighted by the traffic volume in bus-layer. We fit all layers by using the power-law distribution and validated by the chi-square goodness-of-fit test. We denote the degree as x associated with the corresponding probability as f(x). In Changchun, the bus-layer follows f(x)=11.94 ∗ x−0.923 with r2 as 0.99. The taxi-layer follows f(x)=6.485 ∗ x−0.804 with r2 as 0.97. In contrast, the bus-layer in Britain follows f(x)=4.866 ∗ x−0.684, with lower r2 as 0.73.