The Chief of Police or, in the Chief's absence, the ranking officer on duty, is authorized to place emergency traffic control devices at intersections governed or controlled by traffic lights, traffic signals or other traffic control devices whenever such lights, signals or devices are rendered impaired or inoperable. Included among such emergency traffic control devices, by way of illustration but not limitation, are road flares, portable signs, barricades and emergency generators. The authority to place emergency traffic control devices conferred by this subsection is intended to supplement and not to limit such emergency powers as are conferred upon the Police Department by law.