High-speed rail (HSR) is frequently seen as a promising alternative for long-distance travel by air and road, given its environmental advantages whilst offering a competitive level of service. However, a European HSR-network is yet to be realised, with the current state amounting to a patchwork of poorly connected subnetworks. Consequently, this results in a suboptimal performance from a user, operator and societal perspective. We present a customised version of the Transit Network Design and Frequency Setting Problem (TNDFSP) for the long-distance transport context and HSR in particular. We apply an adapted version of a heuristic solution approach to analyse the users’, operators’ and societal performance of a European HSR-network by conducting an extensive series of experiments to test the network's performance under various policy priorities and HSR design variables. Our experiment results show that designs resulting from the consideration of externalities yield more extensive networks with larger coverage and modal shifts. For such networks to materialise, high public investments are needed. The obtained network designs contain four different line types, exhibit spatial disparities in network density, and allow for the identification of potential hubs and critical infrastructure. The strong network integration with overlapping and border-crossing lines of substantial lengths highlights the importance of cross-border cooperation and rail interoperability. We hope our findings will contribute to the ongoing public and professional debates on designing an attractive and competitive European HSR-network.

High-speed rail (HSR) is frequently seen as a promising alternative for long-distance travel by air and road, given its environmental advantages whilst offering a competitive level of service. However, due to a lack of knowledge on the design of HSR specific line configurations and the prioritisation of national and railway company interests, no real European HSR network has been realised yet. Together, these lead to a sub-optimal performance from a user, operator and societal perspective. This research is the first attempt to apply the more frequently used ‘Transit Network Design and Frequency Setting Problem’ (TNDFSP) in an HSR setting, which searches the ideal set of lines and associated frequencies in a given network. To do so, this study developed a novel HSR generic model and solution algorithm, which were then parameterised for the European case. By benchmarking the current situation; analysing the relative importance of vehicle, passenger path and line design variables; evaluating pricing and governance strategies; and finally proposing improved settings; it was possible to assess the impacts of improved design. The experiments showed that benefits for all stakeholders could be simultaneously enhanced when implementing a centralised governance and internalisation of external costs. This allowed the HSR market share to evolve from 14.7% to 29.9%, whilst also improving the societal cost-benefit ratio by 20.0%. The governmental investment which is required to fill the gap from the most economical to the most extensive solution equals AC 2.2 billion per year, but also provides a positive rate of return of 1.8 for the combined user and societal benefits. Additionally, the model demonstrated the necessity of spilling unprofitable passengers and the importance of improved cooperation. These followed from the strong network integration with overlapping and border crossing lines of substantial lengths, the contradiction between national and international interests and the high number of critical infrastructural elements. All in all, this study demonstrated the possibility of using the TNDFSP in an HSR setting, which opens ways for further understanding of HSR network design. For this specific research, it allowed the identification of substantial opportunities for mobility and sustainability. These can be reached by improved design choices, internalisation of external costs and by relaxation of the desires for a competitive railway market and national sovereignty; all newly underpinned arguments for the discussion on how to design a successful (European) HSR system. Future research could greatly contribute by incorporating the construction of infrastructure, including timetabling or operational aspects, assessing different case studies in size and geography or introducing new technologies.