Every motor truck having an unladen weight of four thousand pounds or more and every truck tractor, irrespective of weight when operated upon any street or highway during darkness, shall be equipped with and carry at least two flares or two red lanterns or two warning lights or reflectors, which reflectors shall be of a type approved by the state department of highway patrol. When any vehicle above-mentioned or any trailer or semi-trailer is disabled upon streets or highways outside of any business or residence district within this city and upon which street or highway there is insufficient street lighting to reveal a vehicle at a distance of two hundred feet during darkness, a warning signal of the character indicated above shall be immediately placed at a distance of approximately one hundred feet in advance of, and one hundred feet to the rear of, such disabled vehicle by the driver thereof. The continuous flashing of at least four approved class A-Type I turn-signal lamps, at least two toward the front and at least two toward the rear of the vehicle, shall be considered to meet the requirements of this section until the devices mentioned above can be placed in the required locations. The warning signals herein mentioned shall be displayed continuously during darkness while such vehicle remains disabled upon such street or highway. (Ord. 858 NCS §1; prior code §15.10.13.)