Light signals to control traffic at level crossings etc
39.—(1) Light signals for the control of traffic at level crossings, swinging or lifting bridges, tunnels, airfields or in the vicinity of premises used regularly by fire, police or ambulance service vehicles shall—
(a)be of the size, colour and type shown in diagram 3014;
(b)be illuminated in the sequence prescribed by paragraph (2); and
(c)have ES compliant signal heads.
(2) The sequence for the illumination of the light signals prescribed by paragraph (1) shall be as follows—
(a)a single steady amber light,
(b)two intermittent red lights, each of which will be shown at a rate of flashing of not less than 60 nor more than 90 flashes per minute, and in a such a manner that one light is always shown when the other light is not shown.