Decision-Making in the Transport Sector: A Sustainable Evaluation Method for Road Infrastructure

The transport sector is often the center of political and scientific debate on sustainability due to negative externalities produced by the daily movement of goods and people which impact both on the environment and on quality of life. Great interest has therefore focused on impact estimation of transport infrastructures/services with respect to social, economic, and environmental sustainability. Among the consolidated assessment methods, the cost–benefit analysis (CBA) is one of the quantitative tools representing the final stage (decision) in decision-making processes, which compares design alternatives and verifies the sustainability of a transport project. Recently the Italian Government proposed the national “Guidelines for Assessment of Investment Projects” based on CBA. The aim of this research is twofold: a) from a research point of view, to propose a sustainable evaluating method for impact assessment of the new transportation infrastructure aimed in performing both rational and shared decisions with the territories; b) for a practical point of view, to propose a first application of the CBA Italian guideline useful for the professional practice in the field of public investment evaluation. A quantitative impacts assessment of social, economic and environmental sustainability was performed for a revamping project of a new “greenway” in the south of Italy. Furthermore, also the social equity impacts produced by the new road infrastructure was also quantified, estimating the GINI indexes variation as a measure of effectiveness.