Why are certain shapes used for certain signs?

20th August 2014 | Warning Signs, Health and Safety Signs

Take a look around any workplace where safety signage features heavily and you will see a range of shapes. Rectangles, triangles and circles will litter the workplace, each one meaning a different thing. But why are these different shapes used for safety signs? They don't affect what's written on them, so why not make them all simple squares?

The answer is simple: the different shapes make the signs easy to interpret, potentially to the point where they have saved lives. In a crisis situation, being able to interpret something as quickly and comprehensively as possible can make all the difference, so choosing the shapes for signs is incredibly important.

Take standard warning signs, for example. Think about them - whether you imagine 'wet floor' signs or ones warning about forklift trucks operating in the area, there is a very good chance you are picturing a yellow sign in the shape of a triangle. There is a reason for this.

The triangle has, for a long time, been associated with warning signs in the workplace. This is not because the triangle is inherently dangerous to humans, or conjures up an association with needing to be cautious. Instead, this is a case of an association that has been artificially created by those in charge of workplace safety decades ago.

For some time now, warning signs have been triangular. 'Prohibition' signs - which explain that something is not allowed in an area, such as 'no smoking' signs - are circular, and most other signs are rectangular. These shapes were decided on deliberately in 1968, at the Vienna Convention on Road Signs and Signals.

This is an agreement that 62 countries, including the UK, abide by. It determines what shape and colour road signs should be, as well as a number of their other features. The idea was to create an international 'language' of signs that could be understood across borders, so that if you were driving in a foreign country you would still be aware of hazards.

The agreement decided on the triangle as the shape of all signs warning of a danger - from roadworks to ducks crossing - and the circle for prohibition signs. This was implemented across all the countries covered by the agreement.

As a result, over the years certain sign shapes have become associated with their meanings. When we see a triangular shape, we understand that we are being warned of danger without really having to think about it. This has made these road signs and their shapes perfect to adopt for the workplace.

On the roads, drivers don't have much time to react to danger. When they see a triangular sign, they automatically know to be more cautious long before they can see what is actually on the sign. Most people are fluent in the 'language' of safety signs without even realising it.

In a dangerous workplace, such as a factory floor where lots of different machines are in use at once, the ability to spot areas that might cause injury as soon as possible is crucial. Equally, every worker should be prepared for an area where a certain action, such as smoking, is prohibited.

Much like on the roads, the ability to spot these signs from far off and react accordingly has the potential to save lives. Workers do not have to walk right up to the signs to understand what they mean, before realising there is a danger they are not prepared for.

This is all down to a created association. By standardising the shape of signs, the safety of workers and road users across many countries has been improved hugely. It enables people without a grasp of the language a sign is written in to look at it and know it is warning about a specific hazard.

While many of the aspects of signs play on associations we already make in our minds, when it comes to their shape it is a result of people planning for the future, ensuring that we would associate the same forms with certain hazards for many years to come.