The UK Government has released images of over 600 different road signs which every theory revision application will use to help you prepare. The problem with a theory revision app is that it doesn’t teach you how to understand what they mean. Its all about remembering the picture.

In this blog post we are going to take a look at how you can see a sign you’ve never seen before and decode what it means on the move.

In Theory – The Shape of the Signs

The first thing you need to look at when figuring out what a road sign is saying is the shape of the sign. They come in three general shapes, circular, triangular and rectangular. There are a couple of other shapes but they are for specific signs and we will cover them further down.

Circular Road Signs

Circular road signs are signs giving orders. The shape is picked because its an O for an order, which makes it easier to recognise.

There are two main sizes of sign in use in the UK, the smaller signs, which are about half the size are used as reminders of a previous order. You see them most commonly as repeater signs reminding you when the speed limit is different from what you would expect it to be.

Triangular Road Signs

A triangular road sign is a sign that gives you a warning. Not only is a Triangle a universal sign of a hazard, the sign is also pointing in the direction of it.

Warning signs are used to give advance notice of reasons you may have to change direction or speed.

Rectangular Road Signs

A rectangular road sign gives the road user information. It can come in almost any size, the key is four straight sides.

Depending on the type of road that it is referencing, the colour will change. We will go through this later in the article.

Other Shapes

The GIVE WAY sign is unique in its shape. It is the only sign in the collection which is a point down triangle.

Just as a warning triangle points towards a hazard, the shape of a GIVE WAY sign also gives a clue as to what it means, the sign widens out to a line across your path. You should be prepared to stop at this line.

A STOP sign is another sign that has a unique shape. It is the only sign in the UK that is octagonal.

Regardless of the traffic conditions, you MUST stop at this sign if you see it.

The sign for a level crossing is being phased out and replaced with warning triangles which give more information. However many still remain.

Often they are on a rectangular background, but you can still find signs that are shaped like a cross which hints and the message its is trying to convey.

Uniquely shaped signs are made for a specific reason. When you are approaching these signs it is vital that you know exactly what they mean, regardless of the conditions.

Snow covering the sign, or the sun shining behind can mean that you cant read what the sign says. With these signs, even the silhouette tells you exactly what to do.

In Theory – The Colour is the Key

The next thing to look at when decoding a road sign is the colour. There are a couple of common colour combinations which tend to apply to signs giving orders.

BLUE – You Do

A blue and white road sign is an sign you must do. Look at the sign opposite and decode it like this:

O is an Order
Blue – You must do.
Then you look at the content, which we will go through in the next section.

Red, White and Black – Hold Back

Signs which are red, white and black are signs which are either telling you not to do something, or signs that are warning you about a hazard ahead. The way to remember this is Red, White and Black, you should hold back.

Colours on Information signs.

Non Primary Routes

Information signs giving information on local routes and non-primary routes will have a white background and black text.

A Roads
and Major Routes

Information signs giving you information on A roads and Primary Routes will have white text on a green background. Route numbers will be written in GOLD.

Tourist Attraction Signs

Signs written in white on a brown background are signs referencing sites of tourist interest. One of my personal favourites is for the SECRET NUCLEAR BUNKER.


Signs with a yellow background and black text are either temporary diversions for road works or are signs for short term events of public interest.

You often see these signs around festival sites during the summer.

Motorway Road

Motorway signs are blue and white. They are also written in a specific font which is easier to read at higher speeds.

Ministry of Defence Signs

Ministry of Defence Signs

Some MoD signs are written in black text on a white background. However most MoD signs are red text on a white background.

Signs for
Large Goods Vehicles

Signs with white text on a black background give additional information to drivers of Large Goods Vehicles, such as the best way to get an oversized vehicle into major manufacturing sites.

In Theory – Picture Perfect

There is no way to give you every road sign out there in a quick and easy rule. But, the pictures are designed to be relatively easy to recognise so in this section we are going to look at a number of road signs and decode them for you.

Shape: Circle
Colour: Red, White and Black.
Content: 40 in numbers

Decoding the Sign.

O is an Order.
Red, White and Black – Hold Back.
40 – 40 Miles per Hour.

This one is fairly simple, its a sign showing the maximum permitted speed on the road as 40 miles per hour. Its backed up by the force of law so you can be prosecuted if you don’t obey it.

Shape: Circle
Colour: Blue and White
Content: Arrows forming a circle.

Decoding the Sign.

O is an Order
Blue you must do.
A circular route (Roundabout)

This one is a order sign which is blue and white so you have to do what it says. The image shows a roundabout. Therefore you must treat the next bit of road as a roundabout.

You see this sign on the approach to mini roundabouts, because as they are just painted on the road.

Shape: Triangle
Colour: Red, White and Black.
Content: Arrows forming a circle.

Decoding the Sign.

Triangle is a Warning.
Red, White and Black – Hold Back.
A circular route (Roundabout)

You see this sign on the approach to a ‘proper’ roundabout. A warning that you will have to change speed or direction, telling you to hold back from the roundabout.

The reason this is different from a mini roundabout sign, in that it’s a warning rather than an order, is that if you don’t do what it says, you are going to do damage!

Shape: Rectangle
Colour: Blue and White
Content: Two lanes of traffic with a cycle lane going in the opposite direction.

Decoding the Sign.

Rectangular – Information.
Blue – You must do.
A cycle lane going against traffic.

This sign tells drivers that there is a contra-flow cycle lane ahead. Contra-Flow means against the flow of traffic. It lets you know that you may see bicycles headed towards you on a one way street.

Shape: Triangle
Colour: Red, White and Black.
Content: A car and debris being thrown into the air.

Decoding the Sign.

Triangle is a Warning.
Red, White and Black – Hold Back.
Gravel being thrown from a car’s tyres.

This sign, being a warning triangle, which is red, white and black lets you know you want to go slower. The reason, if you go too fast you risk throwing gravel up at following vehicles or pedestrians.

It’s also a warning not to get too close to the car in front or you risk damage.

Shape: Rectangle
Colour: Blue and White.
Content: Distances to locations.

Decoding the Sign.

This information sign is white and blue which means it’s relating to a motorway. The Motorway is identified at the top of the sign.

The sign shows you the direction of travel, towards the north, then gives you the distances to the centre of the cities listed on the sign.

For more help with your driving theory, get in touch with RPS Driven School of Motoring today. You can also find more information on our social media channels, @RPSDrivenElectric.


Nick Smith is an Approved Driving Instructor working in south Sheffield. Along with automatic driving lessons, Nick is a driving test nerves specialist and offers theory support to learners. A former truck driver, Nick also presents Driver CPC periodic training courses to professional drivers.

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