Most forms of wayfinding signage, like those found in airports or shopping centres, can carry a lot of information as you have time to stop and read the material before moving on. The signage is your primary focus for however long you’re using it. Road signs though, although they do essentially the same job, are used differently to other wayfinding signs; you can’t very well stop in the middle of the road, take your time reading the sign and then continue on! Road signs are designed to be glanced at, not studied. They need to convey the maximum amount of information using the minimum amount of content.
We’re all familiar with the UK’s road signage network. It looks very straightforward, and it is, but in reality a tremendous amount of thought and psychology went into making it so straightforward. Nothing is done by accident or “just because”; every shape, colour and symbol has been designed deliberately in an attempt to convey not only the right information, but in the right way.
The typeface developed for directional signs in the late 1950s, appropriately named “Transport”, has been designed to be as legible as possible even while travelling past the sign at 70 miles per hour. Road signs had previously used upper case exclusively but it was realised that using both upper and lower case was much more effective in aiding word recognition. This is because most of what we read day to day is in mixed case and our brains are more familiar with the word shapes.
When you read a word you’re not actually reading every letter; your brain is tuning in to the overall shape of the word and recognising it. This happens much faster with lower case and the end result is a highly effective and user friendly wayfinding system. So effective, in fact, that many other countries have adopted for their own use the typeface and many of the symbols developed in the UK.
Triggering a Response
The other area of road signs, instruction and hazard symbols, is less universally well received. Most are concise and convey their information very clearly, such as the “stop” and “no left turn” signs, but others don't. The "give way to oncoming traffic" sign’s usefulness is regularly debated on the grounds that it’s illogical and takes too long to work out. Many drivers are unable to even recognise the "no stopping" sign as it makes even less sense; by what means does a red cross on a blue background convey “no stopping”? Hazard signs such as these are supposed to instantly convey a message by relying on your brain making a connection to certain visual cues, and for some instructions the appropriate symbol simply doesn’t exist or is too complex.
Some signs, however, are extremely effective at provoking a response in the brain despite using images that aren’t even necessarily correct. For example the “speed camera ahead” sign features a 19th Century-style camera that bears little resemblance to a speed camera, but motorists still instantly recognise the message. Railway crossing signs still all feature steam trains and tram signs resemble something from the Victorian era.
All of these vastly outdated images are still used because they are intrinsically linked in our brains with the object, much more so than their modern replacements are. Ask anybody to draw you a train and they’ll draw you a steam train rather than a modern diesel-electric.
Colour and Shape
Even the shape and colour of road signs is not an accident and relies on our brains making certain associations to be effective. Different colours provoke very different reactions in the human mind. The brain is very sensitive to the level of energy in the light that passes through your eyes, with different colours of light carrying different amounts of energy.
Orange and yellow are associated with positivity and are used for roadworks information signs to encourage frustrated drivers to think beyond the current delays. Motorway signs are blue as the colour suggests harmony, relaxation and consideration of others; ideal for motorways where high speeds and busy rush hours can result in serious accidents if road users are stressed and aggressive. Can you imagine if motorway signs were all red?
Differences in shape also create different psychological reactions. Warning signs are triangular as the brain associates the sharp points with danger while information signs are rectangular as this is the same shape as a book, something firmly rooted in the mind as a provider of information. Instruction signs are round to resemble the end of a pointing finger giving an instruction.
Fade into the Background
Despite the huge amount of thought that went into all these designs, typefaces, symbols and shapes, the key is that people shouldn’t even notice them. The last thing you want to happen when you're driving along at 70 miles per hour is to be distracted thinking “look at that lovely design”. All you want is to be told where you are and where you’re going next. Road signs are designed to be glanced at and then forgotten about instantly, which may result in a relatively thankless job but the country would grind to a halt without them!