Visibility In All Conditions
September 09, 2015
Are you a cyclist or runner? If you’ve ever taken a route through a busy roadway, you know how important it is to be seen. The same dangers faced by a recreationalist are present for thousands of workers every day, so many wear high-visibility safety apparel, garments that improve how well other people “see” the wearer, as a precaution.
However there is little information available to help companies make the right selection, especially if they work in shifting conditions, but by understanding the science of visual perception of light and colors, we can learn what it takes to be your safest in any light.
Most often, high-visibility safety apparel (e.g. vests, bibs or coveralls) is worn to alert drivers and other vehicle operators of a worker’s presence, especially in low light and dark conditions. High-visibility headwear can also be worn to increase the visibility of the wear in situations where part or all of their body could be obscured, such as by trees or traffic barriers.
Whether you are outfitting a construction crew or finding your newest windcheater, we have a few rules to elements to look for!
Pick the right colors
We see color by interpreting “wavelengths” of light through our photoreceptors, the color-sensitive cone cells and luminance-sensitive rod cells, in the human eye. In changing lighting conditions, your eyes use different combinations of these cells to interpret exactly what colors you are seeing.
Three colors are the rockstars of visibility: yellow-green, orange-red, and true red. Yellow-green is the best choice during the day – and best all-around choice for a single color. But as dusk sets in and lighting gets dim, orange-red and red start to become more prominent as your eyes adjust to the ambient light levels.
Look for fluorescent
Why fluorescent? Because the most visible clothing appears to glow, or fluoresce, under daylight conditions. These materials are essentially performing a clever trick. When sunlight hits them, a portion of the invisible, ultraviolet light (the same rays sunblock protects you from) is absorbed and reemitted, but at wavelengths humans can see. That’s why a fluorescent jacket or vest appears so bright – almost as if lit up from within.
And at dusk, as the visible spectrum of light shifts toward shorter wavelengths, and normal colors become less visible, fluorescent materials appear even brighter as they retain their luminance and compete against a generally dull landscape.
Add reflective elements
Reflective material is created to bounce light off of its surface so that it can be seen. This property will let a driver to see the light being reflected from the reflective material on a person’s garment when the person is standing in the light’s beam. When color visibility decreases in low-light conditions, these reflect elements can introduce contrast back into the driver’s field of vision.
So the takeaway from all this? The safest, most visible combination of clothing would include all three fluorescent colors and reflective detailing. But if the tri-color scheme seems a bit much, do the bright thing: Pick at least one of them – and wear it!