Abstract: The traffic warning sign is an illuminated display that is monitors the passing of a vehicle. The traffic warning sign determines whether the passing vehicle is in compliance with laws regarding the operation of vehicle headlights of the vehicle. If the traffic warning sign determines that the passing vehicle is not in compliance with the laws regarding the operation of vehicle headlights, the traffic warning sign illuminates a display panel conveying to the vehicle operator a message to turn on the vehicle headlights. The traffic warning sign comprises a housing, a display panel, and a control system. The control system controls the illumination of the display panel. The display panel is a translucent structure that is backlit. When illuminated, the display panel displays an indicia that conveys the sentiment to turn on the vehicle headlights. The housing contains the control system and the display panel.