Comparative specific energy consumption between air transport and high-speed rail transport: A practical assessment

High-speed railways have recently conquered market shares that were previously only covered by air transport, at daily distances up to 600-800 km, or by cars, for journeys of 100-150 km, mainly thanks to the much higher speeds that have been reached by high-speed trains since the late Nineties. However, in recent years, the relevance of the dependence of the transport sector on black-oil and the consequent emissions have drawn attention to the importance of energy efficiency as a significant parameter to compare alternative transport modes in a more complete way than travel time and covered distance. This paper has the purpose of: - quantifying and comparing the specific energy consumption of air transport with that of high-speed rail transport; - determining the ranges in which operating, sometimes also investing, in one of these two modes would be convenient from the usage viewpoint and from an energy perspective; - determining where there is still notable competition between these modes. The comparative analysis has been carried out taking into account original data and assessments linked to energy consumption, but it has also been considered important to investigate several other factors, such as the price of electricity compared to that of kerosene. It has been possible, through the use of rail simulation and of two different air transport simulation tools, to evaluate the consumption of the two transport modes in order to compare the two modal alternatives; rather original outcomes have been obtained. Owing to the presence of a number of variables that can play an important role in a comparative specific energy consumption study on air and high speed rail transport, further analyses are envisaged. However, the present work represents a first, fundamental step towards obtaining a more complete vision of the problem.