A "roundabout" is an intersection –

(a) with either –

(i) one or more marked lanes, all of which are for the use of vehicles travelling in the same direction around a central traffic island; or

(ii) room for one or more lines of traffic travelling in the same direction around a central traffic island; and

(b) with or without a roundabout sign at each entrance.

Note 1 : Intersection , marked lane , traffic and traffic island are defined in the dictionary.

Note 2 : Rule 322 (3) and (4) deal with the meaning of a traffic sign at a place.

Roundabout sign