Public transport (PT) plays a vital role in commuting billions of travellers in cities all over the world, providing a mode that is both sustainable and accessible. Metro networks are especially apt at this considering their high-capacity and high-speed operation in urban environments. Comparing different metro networks to one another is a suitable manner for transport planners to gain insights into the characteristics of their networks and which areas of improvement exist. In the field of network science, metro networks have been studied extensively in recent decades. While this provided many new insights in the field of network science, the practical relevance for the field of transport science often remained limited. This limited relevance is primarily caused by the lack of realism of the network representations used, not incorporating the actual operation and service that the network provides. As such, this study proposes a comprehensive comparison of metro networks worldwide including service information. This comparison study includes service characteristics in the form of the total travel time indicator for shortest path calculations, which is a combination of the in-vehicle time, waiting time and number of transfers. The median of this total travel time is taken for each network and compared to that of other networks. This metric in turn is contrasted with network- and city-related characteristics in order to explore relations between these factors and to explain the patterns discovered. From this analysis, it is revealed that the travel time increases with network size. The indicator that is especially apt at explaining the differences in total travel time between networks is the number of stations combined with the average direct station distance. The total travel time methodology applied in this study shows significantly different results to other commonly used methods that rely only on in-vehicle time or hops to calculate shortest path travel times. The waiting time turns out to be the main contributor to these significant differences. Future studies can expand on this by considering other network science indicators and looking further into local indicators. In addition, the methodology could be expanded with more detailed transfer information and other PT modes.

High-speed rail (HSR) is gaining increasing attention due to its sustainability and transport capacity, aligning with ambitious European transport goals for 2030 and 2050. Despite its potential, the creation of a unified European HSR network faces challenges rooted in poor coordination and national interests. This study addresses the absence of a comprehensive, long-term strategy for establishing such a network, with a specific focus on critical infrastructure development. It introduces an iterative network growth model to determine where, when, and at what cost HSR infrastructure should be built under centralized decision-making processes given current budget allocations. The approach analyses the dynamic interaction between infrastructure expansion and the long-distance transport market demand distribution. Results emphasize the benefits of adopting centralized decision-making and appraisal processes, highlighting that achieving these goals requires a comprehensive, collaborative effort, as well as a proper European institutional investment management with more spending power.

Hierarchy is a network property that identifies the organisation and importance of network elements. Public transport systems consist of stops organised by connections, which can be regarded as networks. In a Public Transport Network (PTN) with a high hierarchy, the number of elements gradually decreases as their importance increases, where the majority of elements have low importance and a few high-important elements. The hierarchical organisations in PTNs contribute to the network performance by efficiently allocating resources based on the elements' importance. The hierarchy has been studied in transport with different methods and data sources. However, the topology-related quantification and comparison methodologies of PTN hierarchy and its mode-wise and continent-wise effects are scarce. A unified PTN hierarchy definition and the quantification methodology are necessary to enable PTN comparisons in terms of the network organisations and reflect the relative PTN performance. Based on the current research gaps, this study develops topology-based PTN hierarchy quantification and comparison methodologies. First, six topological characteristics of PTN hierarchy are identified from the element scale (vertex accessibility, element intermediacy and vertex cluster importance) and network scales (scale-free structures, high-clustering structures and vertex connection pattern). Second, six element-based or network-based topological indicators are selected to quantify the topological characteristics. For element-based indicators (vertex degree centrality, closeness centrality, betweenness centrality and eigenvector centrality), the coefficient of determination (R square) of the indicator's probability density distribution fitting the skewed normal distribution represents the PTN hierarchy. For network-based indicators (modularity coefficient and assortativity coefficient), the quantified indicator values represent the PTN hierarchy. Next, the radar chart is developed for comprehensively assessing the normalised six-dimension PTN hierarchy. To evaluate the performance of the methodology, a database based on the GTFS data containing topological information of 63 high-capacity unimodal PTNs worldwide is applied with the hierarchy quantification methodology as a case study. In the PTN hierarchy comparison, the hierarchy in the closeness centrality and betweenness centrality are prone to be high and have higher importance for PTN operation, reflecting the hierarchical organisations of stops' accessibility and the traffic intermediacy on infrastructures. PTN hierarchy in the eigenvector centrality and network modularity dimensions reflect the mono-centric or multi-centric network structures. In the vertex degree centrality and network assortativity dimensions, the identified PTN hierarchy topological characteristics are less significant. In mode-wise effects analysis, the order of modes having PTN hierarchy from high to low is metro, tram and BRT networks. The continent-wise effects show that the European PTNs usually have a higher hierarchy than North American PTNs. Overall, the research offers a unified topology-based PTN hierarchy as a network property. This study's quantification and comparison methodologies bring a comprehensive multi-dimension and intuitive perspective for PTN hierarchy with the radar chart representation. With the case study, the six-dimension PTN hierarchy, the mode-wise and continent-wise effects are analysed. The methodology benefits the universal PTN performance comparison with basic topological information.