Micro-scale sustainability assessment of infrastructure projects on urban transportation systems: Case study of Azadi district, Isfahan, Iran

Sustainability assessment and sustainability indicators are familiar terms that have gained significant importance. Non-compliance between the sustainable development principles and transportation infrastructure projects is changing the appearance of historic cities from livable and vibrant atmosphere into the car-oriented condition and cause environmental and social problems. There exist numerous studies on measuring the sustainability of transportation at the country, state, city, and even traffic zone levels, but few have addressed the sustainability of micro-scale projects. The objective of this study is to assess the sustainability of infrastructure projects on urban transportation systems and evaluate their compliance with principles of sustainable development. According to made intensive field visits, run expert interviews, and development master plans relevant to the case study, nine scenarios are proposed to improve the traffic situation of Azadi district in Isfahan city. Obviously, a slight change in the urban streets network, would have a significant effect on traffic performance in larger area, therefore, all the proposed scenarios are modeled in Trans Cad 5.0 software environment to determine their influence area (IA) as the study area. Ten quantitative indicators in three dimensions (environmental, social, and economic) pertinent to the urban transportation are selected based on review of the related literature and available data in Isfahan. The IA and all proposed scenarios are simulated and calibrated in AIMSUN 8.0 environment and the indicators are quantified in a direct and indirect manner through AIMSUN outputs. A composite sustainability index (CSI) is applied for integrating the effects of selected indicators based on their rankings given by the experts regarding to the goals of Isfahan vision in 2025. The results indicate that public transportation development projects are the most compliant scenarios with the principles of urban sustainable development and the best options for the future development in Azadi district. This proposed framework, would assist policy-makers and traffic engineers in other cities to evaluate the sustainability of urban transportation infrastructure projects.