Budapest-Belgrade Railway's Hungarian Section Faces Significant Restrictions Amid Train Control System Issues

Limited Operations Begin on Key Rail Link

Freight traffic officially began on the Hungarian section of the modernized Budapest-Belgrade railway on February 27, marking a significant step for the infrastructure project. The first freight train departed from Budapest's Ferencváros station, with a revenue-earning service following hours later. However, the commencement of operations is overshadowed by substantial restrictions stemming from unresolved issues with the train control system.

The Hungarian section, spanning approximately 158.6 to 166 kilometers between Budapest-Ferencváros and Kelebia on the Serbian border, is a crucial part of the China's Belt and Road Initiative (BRI), designed to connect the Port of Piraeus in Greece with Central Europe. While the physical infrastructure, including tracks, stations, and electrification, is complete, the European Train Control System (ETCS), essential for modern railway operations, is reportedly not yet fully operational and lacks necessary authorizations.

ETCS Malfunctions Lead to Severe Limitations

The absence of a fully commissioned ETCS has led to considerable operational constraints. Currently, only one train can operate in each direction across the entire 160-kilometer section at any given time. This means a subsequent freight service can only depart from Ferencváros once the preceding train has reached the Serbian border, effectively imposing a headway of up to two hours.

Furthermore, without the ETCS active, trains are limited to a maximum speed of 100 km/h, which can drop to as low as 40 km/h in conditions of reduced visibility. The line's exclusive reliance on ETCS, without an alternative national system, means only locomotives equipped with this specific system can operate, thereby restricting operational flexibility.

Interoperability Challenges and Passenger Service Delays

Beyond the domestic control system issues, cross-border interoperability between Hungary and Serbia presents additional hurdles. The technical compatibility between Hungary's EU-standard ETCS and Serbia's Chinese-origin system has not been fully resolved. This incompatibility currently prevents electric locomotives from crossing the border directly, necessitating the use of diesel locomotives and additional changes at the frontier. Additionally, the maximum train length accepted in Serbia is 700 meters, shorter than the European standard of 750 meters, which impacts the economic efficiency of international freight.

The ongoing technical issues have also cast doubt on the launch of passenger services. While initially anticipated for early March, the full introduction of commercial passenger services is now likely to be postponed until the train control system is fully completed and certified. Testing of the signaling and control systems, including the ETCS, was conducted by a special test train operated by Deutsche Bahn Systemtechnik until February 26.

Project Background and Investment

The Hungarian section of the Budapest-Belgrade railway represents an estimated investment of approximately 1,000 billion forints (around 2.5-2.7 billion EUR). The project is largely financed through a loan from China's Export-Import Bank. Construction on the Hungarian side began in July 2020, with civil engineering works starting in February 2022. The entire 350 km railway project, a joint undertaking by China, Hungary, and Serbia, aims to reduce travel time between Budapest and Belgrade from eight hours to approximately three and a half hours once fully operational. The Serbian section of the railway became fully operational in October 2025.