According to the GDV insurance association, wildlife accidents are the most common cause of accidents in Germany: at least 270,000 larger wild animals are killed by vehicles on the road every year. An optimal solution to the problem has not yet been found, but at least there are various approaches. The blue wildlife warning reflectors are one of them.
How wildlife warning reflectors work
Wildlife warning reflectors | are attached to delineators to visually alert wildlife to the danger and prevent them from crossing the road. There are semi-circular and prism-shaped reflectors. Both versions consist of a plastic base and one or two blue reflective film strips.
The Colour Blue
Wild animals mainly see blue, yellow and green colours. Although light is visible to them up to the UV range, they do not see orange and red and are perceived as shades of green. As blue hardly ever occurs in nature, it is an unfamiliar colour for animals. It is therefore assumed that blue can irritate wild animals. This is why wildlife warning reflectors are usually fitted with blue reflective film | .
Light and Movement
High-performance reflective foil of reflection class RA3 with a microprismatic structure should be used for wildlife warning reflectors. This means that incident light is bounced back and forth within countless small prisms in the film before it is bundled and reflected to the light source.
In addition to colour perception, wild animals have other special visual characteristics: A large proportion of the visual receptors are responsible for the perception of brightness, only a small proportion for seeing colours. As a result, wild animals perceive differences in brightness much more intensely than humans. A sudden bright illumination of the wildlife warning reflectors can therefore surprise and frighten the animals. Another point is the increased perception of movement by wild animals. When a vehicle drives past the wildlife warning reflectors, the angle of incidence of the light changes and the reflections of the film simulate movement. This also alerts the animals.
The effectiveness of wildlife warning reflectors
Although the effectiveness of wildlife warning reflectors is controversial - a recent scientific study denies a significant influence of the reflectors on animals, while many foresters report a reduction in accidents in practice - there is an additional good reason for the use of wildlife warning reflectors:
Not only wild animals are warned of danger by the blue reflectors, but also car drivers! The wildlife warning signs remind road users that deer, wild boar and even small animals such as martens can be expected on the road at any time in the area in question. This allows considerate drivers to reduce their speed accordingly if necessary and increase their attention.
The approval of wildlife warning reflectors
The german Federal Highway Research Institute (Bundesanstalt für Straßenwesen: BASt) permits the use of wildlife warning reflectors as long as they weigh less than 100 g and, together with the delineator, do not weigh more than 6 kg. Authorisation for the installation of wildlife warning reflectors must nevertheless be obtained from the relevant authorities. Depending on the type of road - main road, local road, etc. - different authorities must be contacted. The police are also glad to be informed.