Sustainable pathways for mitigating externalities in long-distance terrestrial transport

International agreements and European policies emphasise the necessity to reduce transport externalities, particularly by focusing on greenhouse gas (GHG) emissions. This reduction should align with improved accessibility to major urban areas, which is a goal explicitly associated with the Trans-European Transport Network (TEN-T). However, the correlation between these two objectives is not necessarily straightforward, as an increase in travel demand may contribute to the growth in transport externalities. This study economically evaluates the transport externalities generated along the Italian segment of the Brenner axis, which is the central part of the TEN-T Scandinavian–Mediterranean corridor. The aim of the analysis is twofold: (i) to ascertain whether the evolution of travel demand over the last decade aligns with European objectives on transport externalities; (ii) to project the expected effects to 2030 and 2040 under alternative scenarios. Existing data fail to reveal a clear trend, owing to fluctuating travel demands in recent years.
Instead of indicating a generalised reduction in externalities, the data reflect a redistribution of costs among categories, with less effects from local pollutants and higher congestion and accident costs. The anticipated increase in travel demand is likely to exacerbate these externalities, thus further increasing road congestion and accident costs. This increase is not expected to be fully offset by the reduction in air and GHG emissions despite the enhanced efficiency of the vehicular fleet. The modal shift from road to rail, as well as the ongoing digitalisation processes, are imperative for effective road traffic management and reducing costs along the corridor.