After a traffic accident, for clarifying questions of blame it is necessary or helpful, inter alia, to know the operating state of lighting elements on a vehicle at the point in time of the accident. In the case of conventional incandescent bulbs, this can be done by various methods of physical analysis of the incandescent wire or of the remaining glass residues of the glass bulb. Such methods for analysis are described in [H. Burg, A. Moser, Handbuch Verkehrsunfallrekonstruktion [Handbook of traffic accident reconstruction], Vieweg+Teubner−Verlag 2009, pages 793 to 800]. In the case of new lighting solutions using LED or xenon, this is no longer possible, since the operating state no longer leaves permanent physical traces on the luminous element. Subsequently determining an illumination state at the instant of collision of an LED lamp system or of a xenon lamp system is possible only in vehicles equipped with central data recording devices.
The disadvantage of a central data recording device is that central data recording devices are very complex and expensive. Therefore, their use is restricted to the field of mid-range and top-of-the-range motor vehicles. In the case of an accident there is the risk of a line fracture or of a signal interruption generally between lighting element and central data recording device. Moreover, the central data recording system only stores desired states of the lighting element. Actual states can only be recorded after a lighting system has communicated its actual state to the central data recording device. This presupposes a certain complexity of the lighting system per se, which in turn is at odds with an economic solution. Equipment with said central data recording devices is not economic for small motor vehicles, and for motorcycles and bicycles.