A roundabout is a type of circular junction at which traffic must travel clockwise around a central island and is designed to keep traffic flowing. The mirror, signal, manoeuvre routine on approaching a roundabout is very important, as is planning your entry and exit lanes. One of the most important details to remember is that you must always give way to traffic coming from your right unless road markings indicate otherwise.
There are different types and different sizes, some controlled by road markings and some controlled by traffic lights.
On a large, multi-lane roundabout your positioning on approach will vary according to which exit you plan to take. If you were leaving at the first exit to the left, this should be treated as a straight left turn, following your MSPSL routine. If you were following the road ahead, you would enter in the appropriate lane for that particular roundabout and would only signal to leave ahead of your chosen exit. If you were planning to leave from the exit to the right of the roundabout, you would approach in the appropriate lane with a “right” signal, changing to “left” after the exit before your exit, (see Diagram A) If you plan to take an exit to the right on a multi-lane roundabout, the most convenient lane could be the middle lane, provided road markings allow, rather than outside lane as you would expect, depending on the weight of traffic, (see Diagram B)
Some large roundabouts have feeder lanes where, if making a simple turn to the left, you can enter and exit the roundabout without stopping, but always check for traffic coming from the right.
Mini roundabouts should be treated as a normal junction, where the usual rules apply, and are nothing more than traffic calming measures. Where there are junctions with two or more mini roundabouts, each roundabout should be treated separately and with care, (see Diagram C)