Section 15 in The Delhi Metro Airport Express Line, General Rules, 2010
15. General.
(1)The following signals shall be used for controlling the movements of trains on the Delhi Metro Airport Express Line, namely:-(a)cab signals;(b)fixed signals; and(c)hand signals.(2)The aspects displayed by fixed signals are the same by day and by the night, in open and in tunnels.(3)A fixed signal be placed, where practicable, on the left hand side of the track to which it refers and shall be visible from such a distance as will enable a train operator to brake a train from forty kilometer per hour speed to stop before reaching the fixed signal and a repeater signal shall be provided at locations where due to obstructions such visibility is not available, except in depot.
