A. Modeling of Interchange Topology

Given an interchange J with n one-way roads and m ramps, its topology model, denoted as GJ = ⟨V, E, T, f⟩. The labels denote how a ramp connects to a road or another ramp. Hence, we have four labels: T = {Out-R, Out-L, In-R, In-L}, where Out-R (resp., Out-L) means the ramp leaves a road/ramp on its right (resp., left), and In-R (resp., In-L) means the ramp merges into a road/ramp from its right (resp., left).

For example, Fig. 1(b) presents the topology model of the interchange J1 (Fig. 1(a)).