Characteristics on hub networks of urban rail transit networks

• An approach is given to abstract the hub networks from urban rail transit networks.
• The hub networks possess small-world property and scale-free property.
• The hub network is a hierarchical network and there is a root in the hub network.
• The root of hub network controls the most properties of hub network.
• The station corresponding to the root of hub network plays the main rule in metro networks.

This paper proposes an approach to extract the hub networks from urban rail transit networks, and analyzes the characteristics of the hub networks. Minsk metro and Shanghai metro networks are given to illustrate the feasibility and effectiveness of the presented method in this paper. By simulations, we discover that the hub networks of urban rail transit networks possess small-world property and scale-free property. Meanwhile, this paper shows that the hub networks are completely different from the corresponding metro networks. Moreover, we find that the hub network is a hierarchical network, and the root of hub network corresponds to the transfer station of metro network which is passed by the most lines in metro network, and the root controls the main characteristics of hub network. In other words, the transfer station corresponding to this root plays the most important role in the urban rail transit networks.