According to EU guideline 2007/35/EG, reflective safety markings, also known as contour markings, have become standard components on most new trailers and semi trailers in Europe.
The guidelines stipulate that large trucks (>7.5t) and trailers (>3.5t) that are released for traffic use carry reflective marking tape to outline the contours of the vehicle.
Around a third of all truck accidents occur as a result of poor vision at night. It is under these adverse conditions in particular that vehicles with reflective safety markings are recognised earlier, and more clearly, as being a truck by following traffic.