(a) Place end load lights described under ORS 816.290 at the extreme rear end of the load, in addition to any other rear light required upon every vehicle, at times when limited visibility conditions exist; or
(b) At any other time, display at the extreme rear end of the load a red flag or cloth not less than 12 inches square.
(2) The offense described in this section, failure to mark end of load with light or flag when required, is a Class C traffic violation. [1983 c.338 §501]