A method is described for detecting a wrong-way driving incident of a motor vehicle on a unidirectional roadway, using a traffic monitoring device. A motor vehicle is recognized by the traffic monitoring device, a moving direction of the motor vehicle is determined based on data of the traffic monitoring device, and a wrong-way driving incident is detected when a moving direction is against a direction of traffic of the unidirectional roadway. A traffic monitoring device for detecting a wrong-way driving incident of a motor vehicle on a unidirectional roadway is provided, which includes a recognizing arrangement to recognize a motor vehicle, a determining arrangement to determine a moving direction of the motor vehicle based on data of the traffic monitoring device, and a detecting arrangement to detect a wrong-way driving incident when a moving direction is against a direction of traffic of the unidirectional roadway.