A network design tool for railway electrification considering the environmental impact

The implementation of railway electrification has been showing significant benefits in reducing harmful emissions and noise regarding sustainable development, as well as in increasing the overall passenger satisfaction. From the transportation insight, the railway electrification is expected to attract higher passengers’ demand, since the increase of commercial speed will influence the reduction of the total travel time, and, consequently, create the competitivity with other transportation modes. Therefore, in this work, we focus on investigating the opportunities for railway electrification by developing a novel Electrification Railway Network Design Problem (E-RNDP), which aims at determining the best set of railway lines to be electrified on existing railway network considering budget limitation. The objective of the proposed model is to minimize overall cost considering electrification, signaling, and CO2 socio-environmental costs. The proposed model has been tested on a real case study in Salento, Italy, where the obtained results highlight the benefits that we can achieve through railway electrification in terms of total CO2 socio-environmental savings. Additionally, for every electrified line, we obtain the optimal number of traction substations considering maximum distance coverage. The obtained solution resulted in CO2 emission savings of around 4716 CO2 tons per year and an environmental improvement of 37.37%. Furthermore, a sensitivity analysis is carried out according to different budget values, which could give insight into correlations between total infrastructure and emission costs to interested parties. Additionally, the proposed model could be applied to any real-size problem solving, and it could be useful for decision-makers to decide where to invest in railway electrification.