Economic Evaluation of Public Transit Systems Considering Uncertainties in Economic Parameters: The Case of City of Qom Metro System

In order to find the most economical scenario/alternative among the different proposed set of scenarios/alternatives, one approach is to perform an engineering economy evaluation, or stated more precisely, a cost benefit analysis (CBA). Within the conventional CBA context, all the monetizable costs and benefits of each decision alternative are determined and the CBA procedure is put forward by these deterministic and exact values. However, when the costs and benefits embody considerable uncertainties, one needs to leverage an adapted tool to be capable to perform the CBA with such uncertainties. In this regard, Fuzzy set theory could be a promising approach to handle the inherent uncertainties in the economic evaluation of the projects. In this paper, the classical equations of the CBA are extended to the fuzzy environment and according to the economic situation of Iran, the interest rate, inflation rate, exchange rate, and the construction period is considered as the fuzzy variables. Subsequently, the proposed fuzzy-CBA approach is employed for the economic evaluation of the Qom metro system. The fuzzy variables used in this paper are selected according to the specific economic situation of the country that was affected by international sanctions, high inflation rates, and mismanagement of the economy.