Describes: - the procedure for evaluating the e.m. interference; - the interference distance to be considered; - the types of coupling to be considered for operating and fault conditions of the high voltage a.c. electric traction systems and high voltage a.c. power supply systems; - the configurations to be considered for both metallic pipeline and high voltage a.c. electric traction systems or high voltage a.c. power systems; - the limits of the voltages due to the electromagnetic interference; and - information on interference situations, calculation methods, measuring methods, mitigation measures, management of interference.