An assessment of the potential contribution of overnight trains to sustainable long distance travel in Europe

• Current growth in night trains insufficient to influence transport decarbonisation. • Significant mode shift from air would require huge growth in night train provision. • 35% of intra-European aviation trips could feasibly be served by night trains. • Large-scale government investment in rolling stock could unlock service expansion. • Night trains in some cases most viable option for low carbon long distance travel. While there has been a recent resurgence in interest in overnight trains in Europe, associated with increased public concern regarding the environmental sustainability of long-distance travel, a systematic literature review revealed that there has been almost no published academic analysis of the extent to which this revival might contribute to transport decarbonisation. This paper helps to fill this gap by providing a high-level quantitative assessment of the extent to which overnight train services in Europe would need to be expanded in order for them to make a substantive contribution to transport decarbonisation. It describes the historical development of overnight trains in Europe, and reviews previous research on this relatively neglected transport mode. It then shows through an assessment of intra-European aviation traffic in 2022–23 that while approximately 35% of this traffic is on routes which could feasibly be served by overnight trains, several hundred additional overnight train services would be required to accommodate even 10% of current air passengers. On average only 3–4 daily return overnight train pairs per year have been added to the European network in recent years despite their supposed revival. Rolling stock availability is currently a key constraint on the expansion of overnight train provision. If overnight trains are to play a meaningful role in the decarbonisation of long distance transport, coordinated large-scale government investment in rolling stock could be necessary to facilitate a step change in service levels. Despite this, overnight trains may still provide the most viable option for providing low-carbon travel on many flows in Europe.