The Science Behind Road Signs

Road signs are pretty much everywhere. Whether they are warning signs, regulatory signs or just simple information signs - we see them every day. And yet, if someone asked you what signs you pass on your way home every day, you might be able to list three or four of them. Or you might just stare at them blankly thinking, ‘Signs, what signs?’

You would think that something designed to keep you safe, and make you behave would be a little more … memorable. Or attention grabbing. But the truth is that a whole lot of research has gone into making sure that you DON’T consciously notice or pay attention to road signs. Rather, your subconscious does all the heavy lifting while you concentrate on actually driving.

This is one of the reasons why road signs are standardised. If every city and town used whatever design they felt like, we would spend most of our time on the road trying to figure out what a certain sign is trying to tell us. And we’d probably only find out the hard way, when our lack of understanding ends with us getting involved in an accident.

So how exactly do road signs work?

Title Case vs ALL CAPITALS

Firstly, people don’t actually read every individual letter in a word. Rather, they tend to recognise the overall shape of a word. When you’re zooming past a sign at however many miles an hour, words that are all in capitals would just look like a BUNCH OF RECTANGLES. But use title case instead, and suddenly we can Read Them Much Faster.

When it comes to reading text, we subconsciously put more emphasis on words that are all in capitals. If a whole sentence or group of words is entirely in caps, then we feel like we're being shouted at and shut out what we've read. So now when we see signs all in caps, we focus and pay attention. Because a quick shout tells our subconscious we need to focus on something important.

Physiology And Psychology Behind Color Choice

Another thing that signs do is use the fact that certain colors automatically trigger certain emotions. While the color red is almost impossible to detect at night without some kind of assistance, and we struggle to judge our distance from red objects, it is also the color we associate with 'bad', 'blood' and 'danger'.

It wasn't until 1954 that the change was made - all stop and warning signs now have red in them. Early studies of our physiology revealed that the eye is most efficient at detecting colors in the yellow and green spectrum, especially in low light conditions - which is why many directional or purely informational signs have blue or green backgrounds.

Maximum Information In Minimal Space

There is no more accurate demonstration of the saying that 'a single picture is worth a thousand words' than what signs give. A simple arrow can tell us in an instant that the road ahead has sharp curves or doubles back on itself. Use a red line to 'cross out' an arrow and we instantly know that we can't turn left or right.

"Dynamic" signs which convey movement using nothing but stick figures or simple images trigger the part of your brain that monitors movement. Not only can they grab your attention as much as a full second earlier, your eye movement increases as you scan for danger. Which means you're far more likely to spot a child darting into the road, or wildlife leaping across it.

If someone told you exactly how much science is behind the development of something as seemingly simple as a stop sign, you would probably laugh at them. But the truth is that an unbelievable amount of research about things like human perception and our physiology lies behind each of them. And the fact that we tend to obey road signs without ever really noticing them shows that all that time and effort has actually been pretty effective!