Device for indicating a hazardous situation during lane change for a motor vehicle

The motor vehicle has a lane change assistance system (8)for detecting a hazard situation during a lane change and detecting any motor vehicles in a lateral and rear region, a lateral and/or rear lighting device (2,3) and a device (9) for operating the lateral and/or rear lighting devices to output a warning signal if the driver intends to change lanes and the lane change assistance system is outputting a hazard warning signal.