There are two rail bridges across the Danube between Bulgaria and Romania – Vidin-Calafat and Ruse-Giurgiu – and the lines to both are electrified on the Bulgarian side, but not on the Romanian side. This means passenger and freight trains have to switch to a diesel locomotive Golenţi (near Calafat) – Craiova (100km), and Ruse via Giurgiu – Rădulești (65km) or Ruse via Giurgiu – Chiajna (84km), although a collapsed bridge at Grădiștea currently renders the latter inoperable. Road traffic at both crossings is prone to long delays, potentially rendering rail transport as a viable alternative, especially for the crossing at Ruse that would be used by Sofia – București trains.
What needs to be done: electrification of the lines Golenţi – Craiova, Ruse – Rădulești and ideally also Giurgiu – Chiajna, so as to allow through trains to run without a change of locomotive
European Commission Analysis
In 2018 the European Commission published its “Comprehensive analysis of the existing cross-border rail transport connections and missing links on the internal EU borders”. The main report (74 pages, PDF) summarises the issues, and Annex 3 of the report (384 pages, PDF) analysed every single border.
For the sake of simplicity, I have made a PDF just of the relevant pages of Annex 3 that cover the 2 relevant Romania-Bulgaria borders – you can find that PDF here.
Photos from these locations