摘要:Abstract Background CO2 emissions are generally considered the most important indicator to determine the global warming effects. Their evaluation in the case of a transportation infrastructure is generally not easy and could be achieved through a separate balance. Method This paper introduces a new heuristic method for identifying the modifications in the CO2 emission balance, deriving from a variation in transportation supply. The focus is predominantly on the construction and on the operational phases, which are listed in all their main elements. The method compares the maintenance of the “do-nothing” option with a number of traffic scenarios resulting from the introduction of a new infrastructure and deriving from different policy measures. Case-study The construction of the Brenner Base Tunnel is used as a case-study for the model, highlighting the role of an enlightened transport policy in the reduction of the CO2 emissions.