Sch 2 para 2.3
Control-command and signalling (2.3.1) Safety The control-command and signalling installations and procedures used must enable trains to travel with a level of safety which corresponds to the objectives set for the network. The control-command and signalling systems should continue to provide for safe passage of trains permitted to run under degraded conditions. (2.3.2) Technical compatibility All new infrastructure and all new rolling stock manufactured or developed after adoption of compatible control-command and signalling systems must be tailored to the use of those systems. The control-command and signalling equipment installed in the train drivers’ cabs must permit normal operation, under the specified conditions, throughout the rail system.