Motor vehicles used for rural mail delivery which display flashing lights, except those owned or leased by the United States postal service, shall comply with the following lighting specifications:
(A) The lighting assembly may consist of at least one and not more than three roof-mounted, flashing, rotating, oscillating light(s) or strobe-type light(s).
(B) Each light shall be amber in color when illuminated. Each light shall be of not less than twenty-one candle power, and shall be visible from a distance of at least five hundred feet to the front and rear of the motor vehicle. Side visibility is also permitted.
(C) All flashing lights required by this chapter are to be visible from the front and rear of the vehicle.