A cost-benefit analysis based on the carbon footprint derived from plug-in hybrid electric buses for urban public transport services

摘要

Sustainable mobility and green development are based on the achievement of three goals: environment, society and economy. This means that a sustainable plan/project must be, at the same time, equitable, viable, and bearable. In urban areas, the transport sector significantly impacts with respect to both fuel consumption and environmental emissions. At this aim, planning policies aimed at reducing these negative impacts are very important. Many researches cover the problem of perform rational decisions to improve the transportation sector. One of the most useful quantitative methods to evaluate rational project solution is the cost-benefit analysis. In literature the "traditional" cost-benefit analysis not always take into account the overall carbon footprint of a transport project/policy. The "carbon footprint" is the total (direct and indirect) amount of greenhouse gas emissions caused by a project/policy/service expressed as the overall amount of carbon dioxide equivalent emitted. Moreover, the recent economic crisis has made necessary also to generate a "profit" from transport services/infrastructures, as well as positive impacts for users and for environment. Starting from these considerations the aims of this paper were: i) to evaluate if the use of hybrid electric buses for a new urban public transport services could produce profit for a private/public transport operator; ii) to develop a cost-benefit analysis explicitly considering the overall carbon footprint (and not only the local impacts) produced by this vehicle technology. The case study was a new urban bus line designed in a medium size city, Salerno, in Italy. The results of the study underline that the use of hybrid electric buses could produce a profit for private/public transport operators and the analysis based on the overall carbon footprint allow to better estimate the (positive) impacts deriving from the use of this vehicle technology. Since the hybrid electric buses have a carbon footprint -12/18% lower than a traditional bus, an urban transportation service based on this type of technology allows to obtain grater benefits up to +82% against a traditional one.