Fig. 3

Simplified example of the directed train network construction. Station nodes α, β, and γ represent the physical stations and dotted red links represent access links that connect the station to each platform. Each type of train on each train route is represented by a separate platform node (black nodes 1−−7) which are connected to other lines at the same station by dashed blue transfer edges. Platforms are also connected to platforms of the same line at other stations by train route edges (gray). In this stylized example, lines 1+2 and 3 both use stations α and γ, but line 3 represents an express train that uses the same tracks without stopping at station β. Only the station nodes are connected to nodes of the other transportation networks. The bus network has a similar construction