Schmierer, G.G.SchmiererMeissner, A.A.Meissner2022-03-082022-03-081999https://publica.fraunhofer.de/handle/publica/304332NOVELTY - The method involves recognizing danger spots through vehicles moving relative to them, whereby the danger spots emit signals with predetermined frequencies and limited range, and the vehicles receive these signals and cause an alarm display corresponding to the respective signal. The alarm display results in dependence on the direction of the respective relative movement between a danger spot and the vehicle, preferably under utilization of a Doppler effect. USE - For e.g. warning about roadworks, railroad crossing, traffic lights, etc. especially in badly visible location. ADVANTAGE - Provides additional information whether danger spot does actually currently exist.de608670patent1997-19740381