Ecological Footprint Analysis of Tramway Track Structures

Abstract

The European urban landscape has been constantly evolving in the last 70 years since the Second World War. Thus, European cities are developing their own public transport networks. Urban rail transportation, namely trams, can be considered a mobility option with (1) high capacity, (2) relatively low life-cycle cost, and (3) low Greenhouse Gas (GHG) emission. Developing green urban transport systems requires, however, using a more comprehensive and complex approach. To do this, infrastructure operators should consider the environmental aspects of construction projects in the decision-making process. This article analyses the construction and maintenance issues of a very common and widespread tramway superstructure from the environmental point of view, using the methodology of ecological footprint calculations. Considering environmental impacts is highly recommended as early as the design stage by selecting the most suitable construction materials and technologies. Therefore, structural and vibration-damping solutions are compared that are equivalent in terms of technical suitability to highlight CO2 emissions and ecological footprint during the production and life cycle of each building material. The results suggest that a multi-directional assessment can help to develop a more sustainable, liveable and environmentally friendly urban transport without major trade-offs. The article also shows how the ecological footprint of the designed track structure changes when it is optimised to minimise the environmental impact. Such a change could result in a reduction of up to 20 % in the ecological footprint.