(1) A sign with the words "OVERSIZE LOAD" or similar wording shall be mounted at any visible height on the front and rear of the load. Letters shall not be less than 8 inches in height. The letters shall be dark in color on a light colored background.

(2) On the power unit, flashing amber lights, a minimum of five inches in diameter, 50 candlepower, 60 to 90 flashes per minute, shall be mounted at each end of the oversize load sign. A revolving light or strobe light may be substituted for flashing lights. Lights shall be flashing at all times when moving an oversize vehicle or load.

(3) Flag vehicles may be required under ARM 18.8.511A in lieu of "oversize load" signs and flashing lights.

(4) Towing vehicles must be equipped with two-way radio communications if flag vehicles are required under ARM 18.8.511A.