If you are transporting explosives and your vehicle breaks down, you may notify other drivers:

If your vehicle breaks down on the road while you are transporting explosive materials, you must warn other drivers. Put out warning signals like reflective triangles or electric lights if you are carrying Division 1.1, 1.2, or 1.3 explosives. Do the same if you are driving a tank used to transport Class 3 flammable liquids or Division 2.1 flammable gases, even if the tank is empty. If transporting flammable materials, do not use warning signals that could cause your cargo to catch fire.