The –Szolnok–Debrecen–Nyíregyháza–Zárailway line from Budapest to Záhony via Szolnok, Debrecen and Nyíregyháza is Hungarian State Railways line 100. It is in length and is a double-track main line with 25 kV/50 Hz electrification. The northern section, from Nyíregyháza to Záhony, is designated 100b.
From Szolnok there is a rail connection to Budapest. The Szolnok - Záhony line has become known for the so-called Fekete vonat (black train) which brings labourers to the capital and has been the scene of fights.
History
The initial 98-km segment between Pest and Szolnok was built by the Magyar Középponti Vasút (Central Hungarian Railway) and opened on 1 September 1847. Construction was interrupted by the 1848-49 war of independence and was resumed by the newly formed Tiszavidéki Vasút (Theiss Railway). The Szolnok - Debrecen segment opened on 25 November 1857 and the segment from Debrecen to Miskolc via Nyíregyháza on 24 May 1859. Since January 1855, the ownership and operations-right of the section Budapest–Szolnok had been obtained by the Imperial Royal Privileged Austrian State Railway Company (StEG) in the association with constructing the section Szeged–Temesvár.