Figure 14
From: Gravity law in the Chinese highway freight transportation networks
Testing the modified gravity law with GDP for the daily directed and undirected freight highway transportation networks. (a) The directed network on 15Â January 2019. (b) The directed network on 15Â January 2019. (c) The directed network on 4 February 2019. (d) The undirected network on 4 February 2019