Evaluation of the Florence highway widening plan by means of LCA approach

摘要

The project of boosting the Florence segment of the main Italian highway, linking the northern regions with the southern ones, has been evaluated in this work, by means of Life Cycle Assessment. Basically, the project consists in building a third lane, for both north and south directions, for the highway segment which bypasses the Florence urban area. This route - 22,5 km long between the two outermost Florence highway exits - is intensively used also as alternative local traffic way in spite of urban area crossing. Because of the large traffic flows, slowing-downs and jams are frequently reported, especially during rush hours. Beyond annoyances as comfort reduction, time wastes, and noises, this situation strongly contributes to environmental quality reduction in the suburban area, in the highway neighbourhoods. The present situation and the future scenario of third lane addiction have been compared in terms of environmental effects on a life cycle horizon. Moreover, further hypotheses of lane widening were proposed and assessed and an improvement in the car pool composition - considering low emission vehicles, according to the latest EC directives - was evaluated. Results showed that the third-lane project realisation allows 31% overall environmental load reduction with respect to the present situation scenario. The environmental impact due to the construction and maintenance phases is negligible when compared with the operation phase. The proposed theoretical further lane widening doesn't add any substantial environmental load variation. When considering car pool composition improvement, the third-lane scenario results even in higher environmental load percentage reduction with respect to the present situation scenario.