The objective of a modern signaling system is not only to secure of high-speed ,high-density train operation ,but atso to contribute to the rationatization of railway management. A signalling system is mainly comprised of block systems , signals , interloking , equipment , point switching devices ,train protection devices , level-crossing protection equipment ,centralized traffic control system (CTC) ,and computer-aided traffic control system (COMTRAC)。
A rough history of signaling in japan is as follows:
1872 - 1887 Establishment period
1887 - 1903 Mechanical interloking / Semaphore
1904 - 1925 Electro-mechanical interloking
1926 - 1954 Electric interloking / Color light signal
