Abstract: A compact, ambient light sensitive flashing warning light that is removably attached to a traffic control device to alert on-coming motorists and pedestrians of a roadway condition. A photocell is connected between a light bulb and a battery voltage source so that illumination of the bulb can be made dependent upon ambient light conditions. The warning light includes a tapered attachment leg that is sized to fit through a hole in the top of a conventional hollow traffic cone, such that the warning light is removably attached to the cone by friction. As an alternate embodiment, the warning light may be interfaced with a bracket that is adapted to be fastened to other traffic control devices such as a conventional wooden barricade.