PART ITHE TRAFFIC SIGNS REGULATIONS 1994
SECTION 3WARNING, REGULATORY AND INFORMATORY TRAFFIC SIGNS
Illumination of signs18
1
Subject to paragraph (2), every sign shown in a diagram whose number is indicated in column (2) of an item in Schedule 17 shall be illuminated in the manner and at the times described in column (3) of that item.
2
Where a sign shown in a diagram whose number is indicated in column (2) of an item in Schedule 17 is placed for the purpose of conveying to vehicular traffic a warning, information, prohibition, restriction or requirement which applies only at certain times, the sign shall be illuminated in accordance with that Schedule only during those times.
3
Where a sign shown in a diagram whose number is indicated in column (2) of an item in Schedule 17 is illuminated by means of external lighting, then that means of lighting shall be fitted to—
a
the sign; or
b
the structure on which the sign is mounted or which is otherwise specially provided,
except that if a sign is mounted on a bridge, tunnel or similar structure over a road the means of lighting may alternatively be mounted separately in a manner such as to illuminate the face of the sign effectively.