Joint plan for upgrade of Thessaloniki–Sofia–Bucharest
Bulgaria, Greece and Romania are working on a joint approach to modernising the Thessaloniki–Sofia–Bucharest rail corridor, moving towards closer cross-border coordination on a route long held back by slow sections and border delays.
The three countries say they will pursue a joint funding application for the corridor, shifting the effort from parallel national upgrades to a coordinated corridor plan.
Why the corridor has lagged
The Thessaloniki–Sofia–Bucharest route has been marked by uneven standards, slow sections and border-related delays, despite repeated national investment programmes along parts of the line.
Direct passenger rail services between Sofia and Thessaloniki have been suspended since 2017, highlighting persistent cross-border frictions.
The new approach aims to align national upgrade programmes into a single corridor plan rather than a sequence of disconnected works.
The corridor is framed to carry both freight and long-distance passenger services, with freight reliability and cross-border transit times a central driver given its role linking Aegean ports to the Balkans and onward to Central and Eastern Europe.
What the upgrade is intended to deliver
The initiative is not positioned as a high-speed rail project. Instead, it focuses on lifting baseline performance by raising line speeds to consistent mainline standards where feasible, removing slow sections and reducing border-related discontinuities.
Typical works discussed include track renewals and partial realignments on weaker sections, alongside electrification, signalling and traffic management upgrades.
Additional measures would target stations, nodes and border interfaces, while freight-focused interventions would aim to improve axle load, train length and timetable robustness rather than headline speeds.
Passenger benefits are expected to come through shorter journey times and improved service stability.
Why it matters: The Thessaloniki–Sofia–Bucharest initiative is less about speed and more about coordination. Treating the route as a single corridor could help turn fragmented national upgrades into system-level gains.