From gas to bridges: Romania and Bulgaria on the south–north strategic axis

Razvan Munteanu, Ziare, July 13, 2026

Summary

Romania and Bulgaria are transitioning from simple transit countries into central pillars of Europe’s emerging South–North strategic axis. This integration combines energy infrastructure with road, rail, river, and military mobility to enhance regional security, economic competitiveness, and European connectivity.

1. The Vertical Gas Corridor (VGC)

The VGC is a high-priority energy project designed to diversify natural gas supply routes by transporting approximately 10 billion m³ annually from alternative sources (e.g., the US, Algeria, and Egypt) through Greece, Bulgaria, Romania, and Hungary.

• Bulgaria’s Infrastructure Push: After facing criticism in 2022 for being a regional bottleneck, Bulgaria designated the VGC a strategic priority in 2024. Sofia is currently constructing three key components, with roughly two-thirds of the pipelines already installed:
  • Kulata–Kresna Loop: A 48 km high-pressure pipeline (€67.6M).
  • Piperevo–Pernik Pipeline: A 53 km high-pressure pipeline and compression stations (€51.4M).
  • Rupcha–Vetrino Loop: A 61 km high-pressure pipeline (€180.9M).
• Capacity & Timeline: These projects are scheduled for completion by the end of 2026, boosting gas transit capacity from Greece to Romania by 50% to 70%.
• Commercial Framework: Beginning in the 2026–2027 gas year, a new harmonized tariff policy and flexible capacity-booking system will lower transit costs to attract new suppliers.

2. Broadening the South–North Transport Corridor

Energy security is being synchronized with physical logistics. On January 30, 2026, regional representatives and the European Commission met to align planning for a broader multimodal corridor spanning road, rail, digital, and military infrastructure.

• The Third Danube Bridge (Ruse–Giurgiu): This key project will resolve a major transport bottleneck. The planned 2 km combined road-and-rail bridge has received €6.9 million in EU funding for pre-feasibility studies. Documentation will wrap up by late 2026/early 2027, with construction targeted for 2031–2032. It will feature 15 km of access infrastructure on both sides, linking directly to Bulgaria’s Ruse–Veliko Tarnovo highway.
• Cross-Border Rail and River Enhancements: Immediate priorities include electrifying the existing Ruse–Giurgiu railway line and resuming local ferry services. Additionally, the FAST Danube 2 project is being prioritized to improve river navigability along the shared Romanian-Bulgarian sector.
• Future Regional Hubs: Long-term conceptual studies are assessing additional bridges at Nikopole–Turnu Măgurele and Silistra–Călărași to stimulate industrial growth and reduce economic disparities in border communities.

Interview

In recent years, Romania and Bulgaria have evolved from being transit countries to becoming key players in the development of Europe’s new South–North strategic axis. The Vertical Gas Corridor (VGC) and the road, rail, and river connectivity projects are not separate initiatives, but rather components of the same vision for strengthening regional security, mobility, and competitiveness. For Bucharest, cooperation with Sofia opens up significant opportunities for economic development, leveraging its geographic position, and increasing its strategic relevance within the European Union.

Unaccustomed as we are to looking toward our neighbors, the time has come to shift our perspective.

The Vertical Corridor: From a Regional Project to a European Strategic Priority

The Vertical Gas Corridor is one of the most important energy infrastructure projects being developed in Central and Southeastern Europe, with the goal of strengthening regional energy security by diversifying natural gas supply sources and routes. According to current estimates, the corridor will enable the transport of approximately 10 billion m³ of natural gas annually, facilitating access to resources from the United States, Algeria, Egypt, and other alternative sources.

The corridor is the result of a regional initiative developed within the framework of the Central and Southeast European Energy Connectivity Initiative (CESEC), with Romania—through Transgaz—having been one of the project’s main promoters since 2016. Together with transmission operators in Greece, Bulgaria, and Hungary, Transgaz has helped transform the concept of a south–north interconnection into a concrete infrastructure project designed to strengthen energy security, diversify supply sources, and integrate the regional natural gas markets of Central and Southeastern Europe.

Bulgaria’s investments are shifting the region’s energy balance

While the project had progressed slowly until 2022, the outbreak of the war in Ukraine raised its strategic stakes, with Brussels pressing for the project to be accelerated. This led the Bulgarian Parliament to adopt, in March 2024, a special law declaring the project a strategic priority and approving state guarantees for its financing. Thus, Bulgaria became the first country to begin construction of the individual components of the CVG on its territory, enabling Bulgartransgaz EAD to transport ever-increasing volumes of natural gas from various sources to different end consumers in Central and Eastern Europe.

The three main components of the future gas project, whose primary objective is to increase capacity at the Sidirokastro/Kulata (Greece/Bulgaria) and Kardam/Negru Vodă (Bulgaria/Romania) interconnection points, are:

1. The Kulata–Kresna Loop Project;
2. The Piperevo–Pernik gas transmission pipeline;
3. The Rupcha–Vetrino Loop Project.

Thus, the first component of the CVG project is the so-called Kulata–Kresna Loop Project, implemented in three phases carried out simultaneously: the linear section—a new gas transmission route, a compressor station at Kulata, and a compressor station at Kresna. The project involves the construction of a new high-pressure gas pipeline with a diameter of DN 700 and a length of approximately 48 km. The estimated cost of this component is 67,628,275 euros, excluding VAT.

The second component is the Piperevo–Pernik gas transmission pipeline, which is also being implemented in three parallel phases: the linear section—a new gas transmission pipeline, the Piperevo 2 compressor station, and the Radomir automated gas regulation and compression station. The project includes the construction of a high-pressure gas pipeline with a diameter of DN 500 and a length of approximately 53 km, the Radomir automated gas regulation and compression station, and a related pipeline branch. The estimated value of this component is 51,425,711 euros, excluding VAT.

The third component is the Rupcha–Vetrino Loop Project, implemented in two phases carried out simultaneously: the linear section—a new gas transmission pipeline—and the Vetrino compressor station. The project includes the construction of a high-pressure gas pipeline with a diameter of DN 1200 and a length of approximately 61 km. The estimated value of this component is 180,905,318 euros, excluding VAT.

The construction of these three components and their integration into Bulgaria’s national gas network will ensure an increase of between 50% and 70% in the capacity to transport gas from Greece, through Bulgaria, to Romania.

Thus, while Brussels’ criticism in 2022 was directed primarily at Bulgaria—whose infrastructure connecting Romania and Greece was viewed as the corridor’s main “bottleneck”—Sofia’s efforts have made Bulgaria one of the leaders of this project today.

In terms of implementation, work on the Bulgarian segment of the CVG is making significant progress. Currently, approximately two-thirds of the pipelines have already been installed along the routes of the three ongoing projects. According to the current schedule, these components are expected to be completed by the end of 2026, which will allow the Bulgarian segment of the corridor to be put into operation and the transport of natural gas volumes reserved for this route to begin.

In addition to infrastructure development, the participating countries and transmission system operators are working to establish a commercial framework that will facilitate the use of the corridor under competitive conditions. To this end, at a recent meeting in Athens, the operators involved in the project, together with the European Commission, agreed on a long-term commercial mechanism designed to provide stability and predictability for natural gas flows to the countries connected to this transport axis.

The central element of the new framework is the harmonization of conditions for access to transmission capacity and the introduction of a tariff policy tailored to market requirements. Starting with the 2026–2027 gas year, users will be able to book capacity for daily, monthly, quarterly, or annual intervals, which will provide greater commercial flexibility and facilitate both short- and long-term planning.

These measures complement the efforts made in recent years to increase the corridor’s economic attractiveness. Along the route, transit tariffs have been reduced in two successive phases, and the new commercial package reinforces this process by offering more favorable terms for infrastructure access. It is estimated that these changes will help expand the user base and stimulate interest among new natural gas suppliers in using the Vertical Corridor.

More than just gas: the vertical corridor and the new South–North axis

However, the project’s significance extends beyond the energy sector, as it is part of a broader vision for developing south–north connectivity in Europe. From this perspective, Greece, Romania, and Bulgaria occupy a strategic geographical position.

Consequently, the investments made in Bulgaria contribute both to strengthening regional energy security and to the development of transportation and logistics infrastructure.

To coordinate these investments, the first official working meeting between representatives of Greece, Bulgaria, Romania, and the European Commission, dedicated to the development of the South–North Transport Corridor, was held in Sofia on January 30, 2026. The meeting aimed to synchronize the planning, design, and permitting phases for joint projects so that their implementation would proceed in a coordinated manner and delays caused by administrative procedures could be avoided.

Thus, the implementation of the Vertical Gas Corridor must be viewed in the context of developing a broader South–North connectivity corridor, with energy security and physical connectivity representing two complementary components of the region’s economic and strategic resilience. While the VGC ensures the transport of energy resources between the Mediterranean Sea and Central Europe, the development of road and rail transport infrastructure facilitates the movement of goods, services, and investments along the same geographical axis.

The bridges across the Danube and the new logic of interconnectivity

In this context, the construction of the third bridge across the Danube between Ruse and Giurgiu represents one of the key investments for strengthening connectivity between Bulgaria and Romania. The new bridge will eliminate one of the main bottlenecks on the South–North axis and will complement the energy infrastructure by developing a modern transportation infrastructure capable of supporting increased trade and regional mobility.

The European Union’s strategic corridors are no longer designed for just one type of infrastructure. The vision is for energy, road transport, rail, digital infrastructure, and military mobility to support one another. Thus, if a country invests simultaneously in gas pipelines, bridges, railways, and highways along the same geographic corridor, the result is a much more robust logistics and energy corridor that is more attractive to investors.

There is also an economic rationale. High-performance energy infrastructure attracts industrial investment, and these investments require efficient road and rail connections for supply and distribution. Conversely, the development of industrial and logistics zones generates greater demand for energy. Thus, bridges, highways, and pipelines are not competing projects, but complementary investments that support one another.

The future bridge is of vital importance for the entire corridor and plays a strategic role in connectivity between Southern and Northern Europe, while also helping to reduce heavy traffic on existing Danube crossing infrastructure. The bridge is also among the projects approved for funding under the Military Mobility component of the Connecting Europe Facility.

Meanwhile, the project to build a new bridge across the Danube between Ruse and Giurgiu continues to advance through the preparatory phase, as it is considered one of the strategic investments that will strengthen connectivity along the south–north axis. Currently, the project is in the preliminary studies and planning phase, with the European Commission having approved funding for the pre-feasibility study through the European Climate, Infrastructure, and Environment Executive Agency (CINEA), with a contribution of 6.9 million euros. The total cost of the preparatory phase is estimated at 13.7 million euros, with Romania and Bulgaria each covering half of the remaining amount.

The technical, financial, legal, and environmental documentation is scheduled to be finalized by the end of 2026 or, at the latest, in the first half of 2027. The project aims to build a combined road-and-rail bridge with an estimated length of approximately 2 km, as well as to develop 15 km of access infrastructure on the territory of each country. On the Bulgarian side, the new crossing will connect directly to the Ruse–Veliko Tarnovo highway, currently under construction, contributing to its integration into the South–North Transport Corridor. Provided the current implementation schedule is followed, construction of the bridge could be completed between 2031 and 2032.

Romania and the opportunity for a new strategic axis

Thus, it is necessary to develop large-scale investment projects aimed at strengthening connectivity between Romania and Bulgaria. Among the priority projects is the electrification of the railway line crossing the existing Ruse–Giurgiu Danube Bridge, an investment that will eliminate one of the main operational constraints on cross-border rail transport and enable the continuous flow of trains between the two countries. At the same time, the authorities of both countries are considering resuming ferry service between Ruse and Giurgiu, a measure that could provide additional capacity for crossing the Danube and greater flexibility in the flow of freight and passengers.

In the medium and long term, the strategy for developing Romanian-Bulgarian connectivity aims to expand the infrastructure for crossing the Danube by building new road and rail links. To this end, projects are being analyzed for the construction of bridges at Nikopole–Turnu Măgurele and Silistra–Călărași, which are currently in the conceptual study and feasibility assessment phases.

Increasing the number of Danube crossing points, combined with the modernization of existing road and rail infrastructure, would help strengthen the North–South Transport Corridor and develop a more efficient logistics network in the region. In the long term, these investments have the potential to stimulate the development of new industrial and logistics hubs in the Danube region, attract investment, and support the economic development of riverside communities in Romania and Bulgaria.

Thus, for Romania, the development of the North–South Transport Corridor represents a strategic opportunity to strengthen connectivity with Bulgaria and the countries of Southeast Europe, as well as to integrate the national infrastructure more effectively into the European transport network. In this context, modernizing existing infrastructure and creating new Danube crossing points are essential for eliminating bottlenecks along the north–south axis and for increasing freight and passenger transport capacity.

Of course, from Bucharest’s perspective, the development of regional infrastructure must be aligned with investment priorities and available financial resources, in accordance with the objectives set at the national and European levels. At this stage, particular emphasis is placed on implementing the FAST Danube 2 project, considered a priority investment for improving navigability on the joint Romanian-Bulgarian section of the Danube and for increasing the efficiency of the Rhine–Danube Corridor. Although, in this context, the promotion of new road and rail connectivity projects must be analyzed in relation to the timeline of investments already committed to, Romania must not miss any other opportunities.

This is because expanding transportation infrastructure along the Danube is likely to stimulate the development of new logistics and industrial hubs, facilitate trade, and reduce development disparities in border regions. At the same time, improved connectivity will strengthen Romania’s role in European transport corridors and support the European Union’s objectives regarding mobility, territorial cohesion, and the resilience of logistics chains.

Razvan Munteanu is the director of the think tank Chamber for Excellence in International Affairs and the author of several articles and specialized books; he is also a contributor to international and national media outlets.

Photo: (source: Pixabay, CC0)

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