Guides/Theory test

What Is a 2-Plus-1 Road, and Where Can You Overtake on One?

Updated 22 September 2026 · 3 min read

A 2-plus-1 road (also written 2+1) is a three-lane road with two lanes in one direction of travel and one lane in the other. The direction with two lanes swaps roughly every 2 kilometres, so each side gets a safe overtaking section in turn. The two flows are separated by a barrier or a wide hatched median, so nobody overtakes into oncoming traffic.

Why the road is built this way

The point is to stop the most dangerous manoeuvre on a national road: pulling out to overtake on a single carriageway with traffic coming the other way. On a 2-plus-1 road you never need to. Wait for your two-lane section, overtake in the second lane, and merge back before the lanes drop to one again. The road gives you a chance about every 2 km, which is why the layout is used on busy stretches of the N-roads rather than building a full dual carriageway.

Where you may overtake

Only in the section where your direction has two lanes, and only in the right-hand lane of the two. When your side is down to one lane you may not overtake at all, even if the road looks clear: the barrier or hatching between you and the opposite flow is there precisely to stop it. The theory test calls the two-lane stretch the plain section, and the answer to "where may a driver overtake on a 2-plus-1 road" is: in the plain section, which occurs approximately every 2 kilometres.

• Read the signs ahead: the end of a two-lane section is signed before the lanes merge, so finish the overtake early rather than racing the merge.
• Keep left in the two-lane section unless you are overtaking, so faster traffic can pass.
• Do not cross the hatched median or barrier line for any reason other than an emergency.
• The speed limit is the one posted for the road, normally 100 km/h on a national road. A second lane does not raise it.

How the theory test asks about it

Two questions, both in the car and truck banks: "What does a 2-plus-1 road have?" and "Where may a driver overtake on a 2-plus-1 road?" The wrong options describe dual carriageways, hard shoulders or overtaking in the single-lane section. Truck and bus drivers get the same questions because the overtaking rule does not change with the vehicle.