Consider a directed network with or

Consider a directed network with origin, O close to disaster area as shown in figure 2. Let A represent the total number of
links in the networks with N = {N1, N2, N3,...,Nn} number of nodes. In the event of a disaster, the movement tends towards
major evacuation exit nodes E, F and G. The exit paths from O 1 5 7 3 10
chosen two O-D pair network for simplicity. Obetween
the O and the exit nodes. Let a be any arc (where a A) with flow, xa and travel time ta= {t1, t2, t3,...,tA}