TCDD Signaling system types
TCDD safety and regulation of train movements is done using several techniques:
- DRS: automatic block signaling operated by local signal boxes. This is used only on a part of Istanbul suburbs.
- CTC: automatic block signaling, controlling a large area, regulated and operated from a signaling center.
- TMİ: manual signaling, using mechanical or color light signals (I-Devlet, ...) and / or verbal or written proceed orders, operated by local stations but regulated from a line dispatcher.
- Manual signaling, using mechanical or color light signals (I-Devlet, ...) and/ or verbal or written proceed orders operated by local stations and regulated between the local signal boxes.
- ERTMS: European Railway Traffic Management system is implemented on the new high speed lines and retrofitted to some lines.
Except for a few locations, TCDD is a low intensity, limited speed single line network. Manual signaling is the most frequently encountered.