An automatic single-track block system, which has some intermediate automatic block signals between stations, allows more than one train to leave a station in the same direction set by the direction lever. In general, this system is used with the CTC system to improve the safety of single-track operation and cut back the number of station employees. Fig. 7 Automatic single-track block system
In order to reduce operation costs of some local single-track lines, the development of a more efficient and economical system was required. Accordingly, a new radio block system using micro-electronics was developed and applied to 17 lines nationwide in 1986 (Fig. 8).
