A framework for defining a sustainability rating system for railway track-beds

Railways perform a significant role in the transportation system and they have relevant environmental, economic and social impacts. They are currently engineered optimizing every singular aspect rather than considering a broader system for improving the sustainability of the overall infrastructure. Thus, it is necessary to promote an effort to define a global sustainability framework for conceiving the design, construction and management of railway infrastructure. The Sustainable Rating System (SRS) proposed in this paper is a tool under development that evaluates different alternatives of railway track-bed structure. Inspired by similar efforts in the field of road engineering such as Greenroads and Greenpave, this SRS aims to be the first entirely dedicated to support railway engineers, designers and managers in taking more responsible decisions with regards to the sustainable design and maintenance of railway track-beds. It is based on a library that examines different solutions and treatments for each element of the trackbed and a table of points that assigns different scores to the different alternatives. To achieve the highest score in terms of sustainability it is necessary to maximize the points assigned to every element. In other words, the maximum score requires adopting best practices leading to more sustainable choices such as exploiting the use of recycled materials, reducing the use of non-renewable resources, the energy consumption, air pollutants and greenhouse gas emissions.