1.1. Background Information
The transport corridor connects different geographical European regions, which is essential for the mobility of people and goods, as well as for the development of connectivity and accessibility infrastructure. The favorable geographical location, combined with efficient infrastructures and transport services, is of key importance for the development of the transport corridors. The Trans-European Transport Network (TEN-T) core corridors are a powerful instrument of communication, cooperation, and coordination between different regions in Europe and focus on the most important connections and hubs. The TEN-T network includes all modes of transport (roads, railway lines, inland waterways, maritime shipping routes, ports, airports, and rail-road terminals) and aims at developing connections in the whole of Europe; it is of great importance for the competitiveness of national transport systems of member states. The transport corridor can play various functions such as: ensure mobility of persons and goods; make optimal use of existing infrastructure; facilitate the prioritization of investments in infrastructure, policy reform, and services; increase connections between different regions, improve the quality of service; influence transport planning and development in countries served.
The TEN-T network includes: 75,200 km of roads, 78,000 km of railway lines, 330 airports, 270 seaports, 210 inland ports [1
]. TEN-T comprises two networks: the Core Network includes the most important connections, linking the most important nodes, and is to be completed by 2030; the Comprehensive Network covers all European regions and is to be completed by 2050 [2
The economic-geographical situation of the transport corridors includes transport, commercial and tourist elements and could be improved. The objective of TEN-T network is improved use of infrastructure, reduced environmental impact of transport, enhanced energy efficiency, and increased safety.
The benefits of the TEN-T corridors have been analyzed by conducting an interview with 23 public authorities, infrastructure organizations/companies, private companies, and other organizations in the Baltic Sea region [3
]. Determined as benefits are economic development, EU funding, visualization of goods flows, transport capacity, transport quality, environmentally friendly transport, competitive rail transport, connections to cities, and cross-border infrastructure planning. It was found that the increment of transport capacity and quality are the benefits from the corridor’s development; the harmonization of extensive transnational transport corridors is an opportunity for competitive rail transport.
The transport corridors were studied in [4
] according to the economic development in the corridor region and connectivity of transport networks. The transport demand problem at the trans-European level for road, inland waterways, and rail with respect to a change of total cost of transport, transit time, and speed were studied in [5
]. This is important for transport policy decisions. The model based on Box–Cox approach was elaborated on. The strategic management method STEEPLE analysis based on seven groups of factors (social, technological, economic, ecological, political, legal, and ethical) is applied in [6
] to study the future development of transport corridors between Europe and Asia.
Four European neighborhood countries, Slovakia, Hungary, the Czech Republic, and Poland, named the Visegrad group were studied in [7
] with the purpose of defining the importance of TEN-T corridors in the development of infrastructure connections. Five TEN-T corridors (Orient/East–Med, Baltic–Adriatic, Rhine–Danube, North Sea–Baltic and Mediterranean) pass through these countries. The following indices were used to compare the transport development: total area, population, GDP, GDP per capita, length of waterways, length of roadways, length of railways, and number of TEN-T corridors passing through country. It was found that the most developed corridor is the Baltic–Adriatic one.
The freight corridor performance for the North Sea Region comprising road, rail and maritime networks was evaluated in terms of 24 Key Performance Indicators [8
]. For this purpose, the corridor was separated into a standard set of transport chains, which are assessed by defined indicators. The indicators were summarized into a more concise set, as follows: transport price (€/ton-km), transport time or speed, reliability, frequency of service, CO2
equivalent emissions (g/ton-km), and SOx emissions (g/ton-km).
Railway transport is an ecological type of moving passengers and freight, and has an impact on the development of commerce, tourism and business relations. It is therefore important to study rail transport along the corridors, and to classify the rail networks in order to determine their integrated position taking into account the impact of transport components.
As railway transport is environmentally friendly the European policy aims is to stimulate the modal shift from truck to rail freight transport in inland Trans-European corridors. A European Mega-Corridor which begins in the north in the Netherlands and Belgium and ends in southern Greece and Turkey is studied in [9
] with the purpose to analyze the possibility to substitute trucks by rail freight trains. The following factors affecting transport were compared: energy consumption, emissions of greenhouse gases, noise, congestion, and traffic incidents/accidents. It was found that railway transport saves about 30% in total externalities arising.
The Orient/East-Med Corridor (OEM) is one of the nine core TEN-T network corridors and in spatial terms connects large parts of Central Europe with the ports of the North, Baltic, Black and Mediterranean Seas. The geographical position of the corridor places it as a path between Europe, Asia and Africa. The OEM corridor includes transport infrastructure of eight countries: Germany, the Czech Republic, the Slovak Republic, Austria, Hungary, Romania, Bulgaria, and Greece.
The Orient/East-Med corridor has been investigated by the International Working Group Spatial and Transport Development in European Corridors [10
]. Recommendations for various development aspects have been proposed, such as: enough capacity for freight and passenger transport, increasing speed as required, separation between freight and passenger transport in densely metropolitan regions, stepwise development of passenger transport, elaboration of a strategy for railway development, elaboration of a strategy for integrated development, and strategic planning.
The economic performances of the TEN-T core rail regions and road European networks have been compared with the economic performance of other regions without the core network, by statistical methods [11
]. The 157 TEN-T regions and 87 non-TEN-T regions have been investigated according to their gross value. The authors found out that the TEN-T regions produce three times higher gross value, compared to the other regions.
The European rail freight corridors have been studied in terms of the following indicators: growth of rail freight performance; services of infrastructure managers; transport performance; capacity analysis; transit time; cost reduction for railway undertakings; and socio-economic effectiveness of the railway system [12
]. The study on OEM corridor examines multimodal transport infrastructure, all types of transport, the project related to the OEM development, the potential for transport innovation, emission reduction, and climate-change related to focus on sustainability and sustainable development [13
The Scandinavian–Mediterranean transport corridor was examined in detail, using the interview method. Four categories of interviewers were included: public authority, infrastructure companies, private companies, and other organizations. The research was conducted in order to support the sustainable development of the core network corridors.
A review of the TEN-T policy, high-speed train, and freight development in European corridors is made in [14
]. The European Union transport policy documents and also the sustainability and sustainable development, regarding the Scandinavian–Mediterranean TEN-T corridor, are studied in [15
]. In [16
] the nine core corridors of TEN-T network are analyzed to assess growth, jobs, and climate impacts resulting from investments to be made between 2017 and 2030. The travel impact on the core TEN-T network has been studied by applying TRUS, the European multi-modal transport network model. Transport demand has been investigated by using a European integrated assessment model called ASTRA. An extensive data base of projects along the core network corridors has been obtained.
In the study [1
], a capacity, traffic, and statistic survey of the OEM corridor has been made. The railway markets in the countries of OEM corridor have been investigated in terms of the following indicators: economy; GDP; technical parameters; transport performance in rail passenger and freight traffic on corridor lines and on all lines of member state; rail carriers; infrastructure indicators such as length of railway lines, intermodal terminals, capacity analysis and technical speed. It was found that the interest from the railway transport grows year by year, as the capacity utilization of the infrastructure increases.
The intermodal transport along the transport corridors in Europe is studied in [15
]. The TEN-T East−West Transport Corridor in terms of the intermodal transport terminals has been investigated in [18
] on the basis of literature analysis and questionnaire survey. The problems about the connectivity between railway hub cities in TEN-T network were analyzed in [19
]. It identified the need for interconnectivity by an intermodal integration of rail hubs at three different levels: into the TEN-T system and into regional and local transport rail and non-rail systems. The inland ports are also important for the European transport corridors. An analysis of both sectoral and integrative policy for the Netherlands can be seen in [20
The following criteria that have a most important effect on the operation efficiency of the TEN-T core network have been defined: corridor interaction and information flows (along the corridor), coordination of activities of infrastructure managers, and cooperative activities between intermodal terminals. An empirical analysis of intermodal connections in Europe has been made in [21
]. The TEN-T Regulation has been analyzed, and criteria to determine the compliance of the sections of the TEN-T corridors of both core and extended network have been studied.
The Intermodal Freight Transport Market Structure model was elaborated in [22
] and allows for an analysis of the market structure of intermodal freight transport submarkets to the network level. A mathematical model to allocate flows to nodes, links, and corridors according to their capacities has been prepared.
The European policy on the Trans-European Network for Transport (TEN-T) over the last 25 years describes and analyzes the role of technicians in the decision-making process [23
]. The assessment of infrastructure projects of Trans-European Transport Networks (TEN-T) is made in [24
]. The authors developed a methodology to determine the European added value generated by transport infrastructure projects. The Member States located in Central and Eastern Europe have been studied according to the EU funding invested in transport infrastructure [25
The Hierarchical Cluster Analysis has been applied to investigate transport and logistics in the countries of the Baltic Sea Region [26
]. The authors have analyzed cargo volume by railway, maritime, and road transport between 2004 and 2011 [27
]. Ten criteria, including gross domestic product; export and import volumes; population; investments in road, rail, and port infrastructures; rail infrastructure density; and others have been used.
Freight traffic procedures on the border between Slovakia (TEN-T core network) and Ukraine have been studied in [28
] by applying the critical path method.
The following measures are important to increment railway transport in the European market: efficient timetable planning, trains and vehicles with higher capacity, European Railway Traffic Management System (ERTMS) implementation, adaptation of Rail Freight Corridors, and high-speed rail [29
A four-step methodology is proposed by the authors in [30
] to define the geographic boundaries of the trans-shipment submarkets and provide a market analysis. It was found that the majority of corridors in the European Union are inside highly concentrated origin–destination markets. The nine Core Network Corridors of the Trans European Transport Network (TEN-T) have been analyzed regarding their infrastructure, modal integration, interoperability, and connectivity [31
] the authors have proposed the following indicators to examine the efficiency level of European railway companies: passengers, freight, kilometers of lines, the percentage of electrification, and the percentage of kilometres of double line.
It can be concluded that the previous studies are aimed at fostering sustainable development in the TEN-T network. The methods that have been used are based on statistical analysis [26
], economic analysis [12
], interviews [13
], and networks models [12
The previous studies show that the most important factors to investigate the development of rail transport along the corridors are gross domestic product [1
], growth of rail freight performances, services of infrastructure managers, transport performances [1
], infrastructure companies [12
], population [27
], rail infrastructures [1
], rail infrastructure density [27
], rail carriers [1
], intermodal terminals [1
], capacity analysis and technical speed [1
], and ERTMS implementation [29
Multi-criteria decision making (MCDM) is an appropriate method for ranking the alternatives subject to different criteria. This approach includes different ways of ranking and the method chosen depends on the decision maker and the problem. The MCDM approach as an evaluation tool for decision-making related to European Corridors is discussed in [33
]. The MCDA method Analytic Network Process (ANP) was used in [34
] to investigate infrastructural development strategy for the regions connected through the axis of TEN-T railway corridor Genoa–Rotterdam. Nine subregions are studied taking into account five clusters (namely, economic development, spatial development, rail operation, environment, and logistics).
In the present study, the SIMUS method (Sequential Interactive Model for Urban Systems) [35
] and the multi-measurable statistical method of Cluster Analysis are proposed to assess railway performance. These methods do not depend on experts’ assessment of the criteria. The Cluster Analysis allows for grouping the studied objects. The SIMUS method makes it possible to rank the countries according to multiple objectives. Since experts’ assessment and weights of criteria are not used, subjectivism is reduced when making a decision.