A dual carriageway, or divided highway, is a road with a dividing strip between opposing traffic flows. The dividing strip is called the central reservation.

You must not reverse or turn on a dual carriageway, cross the central reservation, or drive against the traffic.

Even if you missed your turning at a junction or have taken the wrong route you must carry on until you reach the next junction.

On a two-lane carriageway, drive in the left lane except when overtaking.

On a three-lane carriageway the normal ‘Keep to the left' rule still applies. You may, however, stay in the middle lane when there are slower vehicles in the left lane, but you should return to the left lane after passing them. Do not stay in the middle lane unnecessarily.

The right lane is intended for overtaking only. If you use it, move back to the middle lane and then into the left lane as soon as you can, but without cutting in.

At some junctions, the right most lane may be used by right-turning traffic or exit to specific destinations. Look out for direction signs, destination road markings or lane indication arrows and choose the correct lane for your route in approaching junctions.

Dual carriageway ahead

A sign can usually be seen in advance of a dual carriageway. A dual carriageway may cross the road you are on or your road may become a dual carriageway.