High visibility clothing has spread from the work site to the public arena and, as such, has complicated the reasons for hi-viz clothing. However the fundamental underpinning of high-viz is to contrast against the surrounding environment. This contrast does not only relate to clothing but also signage.
Several years ago, a couple of women from Tasmania visited the offices of SafetyAtWorkBlog to discuss the practicality of hi-viz vests for toddlers and small children. The hi-viz logic of the work site is easily applied to the public park or farms. A contrasting colour to the trees or bushland would make it easier to identify someone, like a wayward child. On a work site, the hi-viz is more about identifying a hazard, whether that be a person, an overhead wire or a work boundary.