The current invention relates to a traffic detection device, including a sensor configured to detect an object of interest within its field of view, an energy supply unit, a communication unit, and a housing configured to encase all other components. Further, the present invention also relates to a system and method for assisting mobile robots. The system comprises at least one mobile robot configured to navigate in an unstructured outdoor environment as a traffic participant and at least one traffic detection system, wherein the traffic detection device is configured to assist the mobile robot by providing additional sensor data. The method includes a mobile robot approaching a road crossing, requesting assistance for the mobile robot, a traffic detection device providing at least one assistive function, and in response to the assistive function, the mobile robot crossing the road.