[2] By the arrival of the twenty-first century, Bulgaria's railway network was amongst the most dense of all Eastern European nations, having a total track length of 6,938km, 148 tunnels, 483 level crossings, and 1,016 bridges.

[3] During the late 2000s, the NRIC was engaged in infrastructure modernisation efforts; a key aim of these schemes was to pursue the closer integration of the Bulgarian railway with that of the wider European community.

Work was primarily focused upon those lines than corresponded with Common European Transport Corridor routes; accordingly, improvements were being pursued to bring these into compliance with the technical operational parameters of track, catenary and signalling.

[3] During early 2012, it was reported that the organisation aimed to have completed all work in respect to lines on the Serbian border– Sofia–Plovdiv–Svilengrad–Turkish/Greek border and Plovdiv–Burgas by 2020, which shall permit an elevated maximum speed of 160km/h along those routes while also bringing them into full compliance with the technical specifications for interoperability.

[4] That same year, it was announced that strong financial performance had been recorded at NRIC, permitting the clearance of all debts that were owed to external partners; this turnaround, as the organisation at one point had been facing substantial fiscal stress, was largely attributed to restricting efforts that had, amongst other changes, caused a reduction in staff headcount from 15,000 in December 20009 to 12,600 by October 2012.

[5] To help mitigate financial difficulties, the NRIC adopted various cost optimisation processes and fiscal implementation reviews, including for alternative financing options where applicable.

Furthermore, the agency was actively implementing new computerised management systems, optical cable networks, and digital equipment that would enhance train capacity and safety levels, while new substation apparatus would reduce energy consumption.