The implementation of the TEN-T's policy, and the timely completion of its core and extended core networks, is important for the EU's economy, growth, socio-economic and territorial cohesion. Ensuring the climate resilience of the completed networks is also important to prevent damages and socio-economic losses, resulting from climate extremes. These, as witnessed in the last decade, can be significant. The results of the study show that all transport modes on the TEN-T are subject to the growing risks of heatwaves, river floods, wildfires, and coastal floods, today and even more so in the future. Also, droughts play a role for inland waterway transport. To mitigate or at least reduce the effects of these risks, an investment of around EUR 71 billion (in 2023 terms), has been estimated for adapting the TEN-T to cope with mid-century climate conditions (2024-2075). The Transport Vulnerability Index (TVI) reveals that vulnerability and preparedness to changing climate conditions differs substantially between Member States. Close to half of the estimated adaptation investments are needed for the Member States which are currently not as well prepared to prevent, prepare for, or cope with the impact of these climate extremes. These adaptation cost estimates are conservative as they do not account for all relevant hazards, different levels of severities of climate events, and local variations in the intensity of exposure and strength of adaptation measures. Thus, extensions to our assessment of exposure and resilience are recommended. With regards to the completion of the TEN-T's core and extended core networks, EUR 866 billion (in 2023 terms) of investment has been estimated. Out of the estimated investment of EUR 866 billion, around EUR 201 billion represents the total cost of key cross-border projects and their access routes, and around EUR 39 billion is needed to ensure compliance with specific rail technical standards. The non-completion of the cross-border projects is expected to reduce the international rail traffic by 14 percentage points for passengers and 7.5 percentage points for freight until 2050, relative to the baseline. It is also expected to reduce Gross Domestic Product (GDP) by 0.4% in 2030 and by 0.8% in 2050 relative to the baseline. The GDP multiplier of the investments into the cross-border projects is estimated at 13 for the period until 2040, and at 31 for the period until 2050. The Connecting Europe Facility (CEF) has been identified to play an important role for the timely completion of cross-border projects and the development of high-quality, sustainable infrastructure which ensures interoperability, intra-modality and the availability of more alter-native route options. European co-funding by the CEF is particularly important for projects characterised by high engineering complexity, insufficient commercial viability, high upfront costs and a lack of market finance.
