Why Are School Buses Yellow?

Colors not only add to the aesthetic appeal of things, but they also make our lives much easier in many ways. Take traffic lights, for example; how would you like it, if, instead of the red-yellow-green light system, they flashed written messages on a screen telling you to stop or go? It may be all right for some people, but for the majority of citizens, color coding does a better job. This is just one of the many instances where colors make things more convenient for us.

However, in some cases, in addition to adding convenience, colors make things safer for us too – school buses are an excellent example of this.

Importance of safety in school buses

School buses, as we all know, have a huge responsibility riding on their yellow shoulders; carrying millions of students to and from school on a daily basis… that is one HUGE responsibility. Think about it, they transport future presidents, tech-wizards, innovators, sportsmen… basically they carry an entire generation of humankind inside them. Needless to say, they ought to be very careful wherever they go.

Therefore, these buses are not only designed to safeguard their passengers internally in case of a mishap, but also present a striking exterior appearance to make it difficult for anyone to miss them, thanks to their distinctive yellow color.

School buses aren’t pure yellow!

this isn't the 'real' yellow meme

Many of you might be surprised to learn that the color of school buses in the US is not actually pure yellow; it’s a different shade entirely! It is a mixture of orange and lemon-yellow, just like the color of a mango… a very ripe one.

In fact, if you were a stickler, you wouldn’t even use the word ‘yellow’ to refer to the color of school buses; that particular hue is officially termed as ‘National School Bus Glossy Yellow’ in the US and Canada. In 1939, Dr. Frank W. Cyr, a professor at Teacher’s College, Columbia University, held a conference, where various standards for school buses in the US were decided upon, including the standard yellow color, which was known as ‘National School Bus Chrome’ back then.

However, was there a definitive reason(s) why they exclusively chose yellow?

Why the color yellow?

If you like investigating stuff from a scientific perspective, you would already know that the color red has the maximum wavelength (about 650 nm) among the various components of white light, and therefore doesn’t get scattered easily and is clearly visible even from a distance. Since red is commonly associated with caution, wouldn’t that be a more suitable choice? Why, then, did they choose yellow instead of red to paint school buses?

There are three main reasons behind their decision….

Yellow’s distinctive appearance

There’s something distinctive about the school bus-yellow that grabs our attention instantly. It has been observed that among the colors we usually come across in our daily lives, yellow is the most visible color to the eye. Take a look at this picture and see if that reality applies to you:

Yellow bus in traffic

What’s the first thing you notice in this aerial view of a city’s traffic? (Photo Credit : commons.wikimedia.org

Favorable in conditions of dim lighting

Due to its somewhat ‘illuminating’ nature, the color yellow is relatively visible in dim light or darkness. Since so many school buses are required to transport kids to school early in the morning – when it’s still relatively dark – yellow is an ideal choice for the color of school buses.

Humans’ peripheral vision

In terms of scientific objectivity, this is the most important reason for school bus color choice, and one that helps yellow trump all others. Scientists claim that the lateral peripheral vision of detecting yellow is 1.24 times greater than it is for red. In simple terms, this means that you are 1.24 times more likely to spot a yellow object, even when you’re not looking straight at it, thanks to the lateral peripheral vision of humans, which helps us perceive things that don’t lie in our direct line of sight.

Peripheral vision

Peripheral vision of humans (Photo Credit : Wikimedia.org)

Those were just some of the reasons why school buses are painted with that signature yellow hue. However, on a more practical note, you can’t have a non-yellow school bus operating in the US, because it’s against the law!


School Bus Yellow / Wikipedia
Chrome yellow / Wikipedia

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About the Author

Ashish is a Science graduate (Bachelor of Science) from Punjabi University (India). He spends a lot of time watching movies, and an awful lot more time discussing them. He likes Harry Potter and the Avengers, and obsesses over how thoroughly Science dictates every aspect of life… in this universe, at least.

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