Evaluation of Sustainable Developments of Railway Corridors: High-Speed Rail Compared to Airplane for CO2 Emissions

The increase of carbon footprint and the climate change scenario are central themes of the current technical and political debate on the world stage. An important contribution is provided by the transport of passengers and goods. Over long national distances, the problem becomes even more crucial. In a nutshell, the carbon footprint of High-Speed Rail (HSR) is on average, lower than other modes of transport, such as private cars or airplanes, for the operating phases. The reduction of carbon emissions with the use of HSR for passengers’ trips at national scale would make it possible to pursue the Sustainable Development Goals (SDGs) included in the 2030 Agenda, with specific reference to Goal 13: “Climate change.” It is necessary to carry out an analysis of the current scientific literature on this topic, considering the levels of environmental impacts in relation to the operative phases of the HSR, through an analysis and comparison of the values of the indicators. The purpose of the paper is to give a synthetic answer to the problem: how sustainable is the HSR systems in terms of carbon footprint and in terms of climate change scenario? The results will therefore be of two types: on the one hand, parametric values can be defined which can synthetically represent the environmental advantage provided by the implementation of the HSR for travel of passengers, on the other hand, the fields of unknowledge in which it is useful to carry out research can be delimited. The reference result is given by applying the synthetic parametric approach to the real case study: the relationship Rome-Milan (Italy). The conclusions of this document allow decision-makers and planners to be supported in the design and construction of new HSR lines with a broader point of view, which considers environmental CO2 emissions and takes solutions to mitigate them.