On January 13, Hungarian State Railways announced that infrastructure construction of the Hungary section of the Hungary-Serbia Railway, which connects Budapest, the capital of Hungary, and Belgrade, the capital of Serbia, has been fully completed. The signaling system on the Hungary section has entered dark mode testing, which refers to conducting closed, isolated, simulated, and comprehensive integrated testing and commissioning, and safety verification of the railway system under extreme operating conditions, without affecting existing line operations or opening the system to external use.