ABSTRACT
The number of cases to consider the disposal of existing infrastructures would increase in underpopulated region due to the decrease in demand caused by the decrease in population, budget constraints, and aging of them. It is required to establish an optimal disposal policy maximizing the total social surplus given by infrastructures. When infrastructures are substitutable each other and the deterioration process changes depending on the demand (e.g. traffic volume), the total social surplus may increase through control of the infrastructures’ deterioration process by controlling the demand of each infrastructure. According to those ideas, we formulate an optimal maintenance/disposal model of two substitutable bridges on a road network. Using the model, we investigated how much total social surplus increase by the optimal traffic control.
