The final Lev 424m ($US 243m) phase of the project involved track upgrades, renewal of signalling and telecommunications, and electrification on the 67.2km section from Dimitrovgrad to Simeonovgrad, Svilengrad and the Turkish and Greek borders.

The modernisation of the line raises the maximum speed to 200km/h for tilting trains, 160km/h for conventional passenger trains, and 120km/h for freight trains.

The project was funded through the European Union's Operational Programme Transport 2007-13.

The line forms part of the Bulgarian section of European Corridor 10 Branch C (Niš – Sofia – Plovdiv – Edirne – Istanbul).