(1) Additional headlamps may be positioned sufficiently high enough to clear operating equipment provided they are aimed at an angle to avoid blinding oncoming traffic while on their routes, involved in construction, maintenance, and/or operations. Except, refuse haulers must:

(a) Use regular mounted headlamps when transporting refuse to the dump site. Auxiliary headlamps may be used if necessary.

(b) Use the alternate lights when the refuse haulers' collections container is in a position to obscure the headlamps, and will not exceed twenty miles per hour.

(2) Additional operating lamps may be located on the top of the cab or at other locations to illuminate plowing, abrasive spreading or other equipment.

(3) No flashing red warning signal except those required by RCW 46.37.150 will be displayed or used on any highway equipment.

(4) Amber colored lamps must:

(a) Be mounted on the cab or other high point of the equipment so as to be visible at all times, at least from the front and rear of the vehicle, from a distance of five hundred feet in normal sunlight, unless otherwise prescribed below.

(b) Have a minimum light intensity of the lamp filament not be less than twenty-one candle power.

(c) Be used on the following vehicles:

(i) Power shovels or other similar highway maintenance equipment. The amber lamp and a red flag are to indicate an extension which designates the maximum danger limit created by the swing of the cab while operating along the traffic lane.

(ii) Other highway equipment which creates a potential hazard to traffic including those vehicles and trailers for construction, maintenance, and operations.

(iii) Knuckle of all man lift-type platform trucks with articulating boom, where the knuckle is capable of being rotated beyond the side of the truck.

(d) Only be illuminated:

(i) When the equipment is actually involved in construction, maintenance, collecting refuse, and/or operations.

(ii) When the equipment is traveling to or from the job site and is unable to maintain, either because of equipment limitations, or other reasons, at least one-half posted or prevailing speed.