Network design model with evacuation constraints

In recent years terrorism activities have been increasing in scope worldwide as well as the global warming process has had a direct impact on the weather in various climates, subjecting countries around the world to unusually severe storms. Thus for the policy maker it is not only a matter of network design (roads and facilities) in terms of costs and level of service for commuting, but also the matter of network design in terms of costs and evacuation time. This paper focuses on the later – the development of a model for the design of an optimal network in terms of minimizing both evacuation time and network constructions costs. However, the optimal model’s complexity does not allow solution within a reasonable timeframe. Therefore, a fast heuristic model was developed based on the minimum-cost algorithm, using the unimodular properties of the model for obtaining integral results. The heuristic algorithm was compared to the optimal algorithm (both based on ILOG CPLEX) on various network scenarios and produced on average 10% higher construction costs than the optimal algorithm. On the other hand, the execution time of the heuristic algorithm was significantly faster than the optimal algorithm.