Different system, that'd be the switches/signalling. Freight and international trains were running just fine, safely. This was literally just planning which tra

Different system, that'd be the switches/signalling. Freight and international trains were running just fine, safely. This was literally just planning which train (rolling stock) is going to operate which train (ride) with which personnel. Safety could be related to duty times, or making sure the rolling stock is fit for a certain trajectory (maximum platform length, weight restrictions etc.)