The high-visibility jacket has been a staple product in nearly every workwear shop since 1964, and are a requirement in a wide variety of jobs.
Whilst there have been particular standards that have been implemented into high visibility clothing since those early years, the principle of high-visibility clothing has remained mostly the same and is built on two similar principles.
Visibility conditions can vary wildly on different sites depending on the time of day, type of lighting and other external conditions, and in practice, there are only two colours that can be seen clearly enough.
High-vis jackets are typically either neon yellow or orange because they are immediately noticeable irrespective of conditions.
In particular, blaze orange is a colour that complements the azure colour of the sky and so is ideal for use on bright, clear days.
This is important, as road workers are often working in low-visibility conditions next to roads that may still be open, requiring them to be as visible as possible to drivers.
During the day, bright colours will typically be enough to ensure a person is seen, but at night, it was not by itself enough to be visible from a distance in poor lighting conditions.
Instead, retroreflective strips are added, which glows brightly when hit by light, making people far more visible on dark roads.
Certain road signs and vehicles also use reflective sheeting to make them more visible in bad lighting conditions, which can be the difference-maker in avoiding an accident on the road in poor conditions.