10. A traffic light signal as prescribed by regulation 13(4) of the Regulations shall be provided on the left hand side of the road on each approach to the crossing along the carriageway and as close as practicable to the barrier. There shall be an additional traffic light signal of the same type on the right hand side of the road on each approach to the crossing so located as to be either in line with or on the railway side of the stop line mentioned in paragraph 12. The traffic light signals on each side of the railway shall be positioned so as to face outwards from the crossing towards approaching road traffic. All the signals shall be capable of directional adjustment.