Have you ever wondered why fire trucks are red?

Whenever we think about fire trucks, the first thing that appears in our mind is a big truck with a red color. Something like this right

Even kids also know the color of fire truck. But have you given a thought why fire trucks are red?

There is no specific, universally accepted answer to this question but there are few theories about the red color of fire trucks.

The first theory is related to the history of automobiles. In 1900, Ford was dominating the automobile manufacturing industry. Due to the durability of black paint, most of the ford vehicles were painted in black color. At that time roads were filled with mostly black vehicles. Any fire vehicle or emergency vehicles should be visible clearly in the crowd of vehicles so that route can be cleared for these vehicles. In order to make sure that the fire truck should stand out in the sea of black vehicles, fire trucks were painted red.

Nowadays also we can find that most of the fire trucks are red.

Now the second theory is related to science of color. Let’s first understand the concept of scattering.

Scattering of light is a phenomenon in which light gets deviated from its straight path due to the presence of dust particles, air molecules, water vapors, etc. This scattering of light affects the visibility of the light. Different colors of light scatter differently depending on their wavelength. The scattering effect is inversely proportional to the fourth power of the wavelength of a color. The color with the highest wavelength will scatter less as compared to color with the least wavelength. Among different colors, red color has the highest wavelength and blue color has the least wavelength. Due to which red color scatters less and is visible from long distance through the fog, rain, etc.

We know that path clearance for emergency vehicles such as fire trucks is important because they should reach their destination on time to save lives and damage to properties. For path clearance, these vehicles should be visible and stand out among other vehicles. Therefore, Red paint is used for fire trucks. But according to a study conducted by Solomon, S.S., and King, J.G on fire truck visibility, it is found that the visibility of red color is good in day time only while it becomes difficult to see red color in poor or low light conditions. Due to this poor visibility, red vehicles are more prone to road accidents. They also found that humans are more sensitive to wavelengths between 510 nm and 570 nm which is mainly covered by greenish-yellow color. While comparing the road accidents of red and greenish-yellow vehicles, they found that the trucks painted with red and white color were involved in accidents three times more than fire trucks with lime green color.

Nowadays most of the fire departments are switching to fluorescent yellow-green and orange due to their high visibility during day time and low light conditions.

You might have also seen that the protective gears of workers are also in fluorescent yellow-green and orange color.