The Traffic Signs Regulations and General Directions 2016

10.—(1) When the road marking is used, studs must also be placed.

(2) The studs must incorporate—

(a) white reflectors;

(b) white retroreflecting material;

(c) a light source that emits, during the hours of darkness, a steady white light; or

(d) any combination.

(3) In the case of the markings shown in parts A and C of the diagram, the studs must be fitted as a single line between the continuous line and the non-continuous line of the marking and be spaced not less than 3 metres nor more than 4.5 metres apart.

(4) In the case of the marking shown in in part B of the diagram, the studs must be fitted either in opposite pairs within the width of each of the two lines that run longitudinally to the flow of traffic or as a single line between those lines and in either case the studs must be placed not less than 3 metres nor more than 4.5 metres from the nest stud in the line.

(5) In the case of the marking shown in part D of the diagram, the studs must form a single line between the continuous line and the non-continuous line of the marking and be spaced not less than 3 metres nor more than 4.5 metres apart and the direction of the line of studs is not to be changed by reason of the switching of the continuous and non-continuous lines of the marking as shown in the diagram at that part.

(6) The external part of the stud that is visible when the stud is in place must be—

(a) white;

(b) of a natural metallic finish;

(c) of another neutral colour; or

(d) clear,

or any combination (but see sub-paragraph (7) for an exception).

(7) The external part of a stud that is visible when the stud is in place temporarily during road works must be fluorescent green-yellow except to the extent—

(a) it consists of white reflectors or retroreflecting material; or

(b) it is necessary for it to be a different colour or clear in order for the stud to emit white light.