Dual carriageway

What is a dual carriageway?

Many drivers get the answer wrong. The most common, incorrect answers are:

  • A road with two lanes
  • A road with a higher speed limit
  • It’s the same as a motorway but without a hard shoulder

Let’s look at exactly what a dual carriageway is. It’s really simple when you know one thing.

What is a dual carriageway?

A dual carriageway is a road that has a barrier separating two directions of traffic.

You can see an example of a dual carriageway in the photo below. I took this photo: where is all the traffic when you need it?

Dual carriageway

The confusion comes from the word dual which means “Consisting of two parts, elements, or aspects.”

The word dual (two) makes drivers think that it has to have two lanes.

Further confusion comes from people spelling it as “duel” and thinking that it’s a duel carriageway from the days of knights jousting.

I made that phrase up myself by the way. It’s not a historical term.

Two knights running towards each other on horses looks a lot like a dual carriageway though as you can see in this photo.

Duel carriageway

What’s the difference between a dual carriageway and a motorway?

Why is a motorway is called a motorway?

Because you must have a motor to go on it.

You can legally go on dual carriageways on a pushbike, on foot or other non-motorised form of transport.

Although it may be legal it is often not wise and I don’t recommend you do it. Many cyclists avoid dual carriageways because they can be so hard to see and many cyclists have been killed by being hit by cars that were doing well under the speed limit.

What’s a single carriageway?

A single carriageway is when two directions of traffic are not separated by a barrier.

Single carriageways are normal everyday roads like those running through many cities across the UK.

I hope that all single carriageways will one day find love.

What’s the national speed limit on single and dual carriageways?

The national speed limit for cars in the UK is 70mph on dual carriageways and 60mph on single carriageways.

It’s different for other vehicles and even for cars if they’re towing a caravan.

Click here for a more detailed list of speed limits.

Are all dual carriageways national speed limit?


I speak about this common driving mistake in the video above. A dual carriageway often has a higher speed limit but not always.

A dual carriageway is just two directions of travel separated by a barrier. It doesn’t automatically change the speed limit.

Do dual carriageways always have 2 lanes?

No, because as you know by now – a dual carriageway is a road that has a barrier separating two directions of traffic!

It has nothing to do with the number of lanes.

They usually have two but the word “dual” is talking about the two directions of traffic, not two lanes.

There are many dual carriageways with 1 lane but they can have any number.

You can read the official highway code definition of a dual carriageway here https://www.highwaycodeuk.co.uk/multi-lane-carriageways.html

If you want to see another thing that many drivers get wrong then check out my page on gas then clutch or clutch then gas?