(1) "Agricultural equipment" means any farm vehicle required by RCW 46.37.160 to have hazard warning lamps.

(2) "Animal control vehicle" means any vehicle, either publicly or privately owned, which is used primarily for transportation of animals to or from animal shelters, humane society facilities, or veterinary medicine facilities.

(3) "Authorized emergency vehicle" will have the same meaning as RCW 46.04.040 except that any vehicle of any federal law enforcement entity will also be considered as an authorized emergency vehicle that need not be classified, registered, or authorized by the patrol.

(4) "C.F.R." means the Code of Federal Regulations.

(5) "Deceleration warning light," excluding stop lamps, means a device that indicates to a following driver the deceleration of the vehicle ahead.

(6) "Electronic light modulation" means the periodic change in intensity of light, controlled by an all electric modulating device in the electrical circuit of the lighting system.

(7) "Electronic modulation" means using ((one hundred))100 percent electronic circuitry instead of mechanical metallic switches.

(8) "Emergency tow truck" means a motor vehicle that is especially designed and constructed principally for the purpose of recovery and/or towing of disabled, abandoned or damaged vehicles and not otherwise generally used in transporting goods or persons.

(9) "Flashing" means any lamp which emits a beam of light which is broken intermittently and regularly by use of an electronic or electric switch, a rotating reflector, a rotating lamp, or a strobe lamp; or a lamp which emits a steady beam of light which is intermittently and regularly directed away from any viewer by means of a rotating or oscillating reflector or lamp assembly. Flashing lamps are not to be confused with modulated lamps which intermittently and regularly decrease the power to the lamp filament so as to dim the light output but do not cause a total break in the light beam.

(10) "FMVSS" means the Federal Motor Vehicle Safety Standards 49 Code of Federal Regulations (C.F.R.) Part 571.

(11) "Hazardous materials response team vehicle" means any vehicle either publicly or privately owned which is used for responding to hazardous materials incidents.

(12) "Headlamp flashing system" means an automatic method for controlling the high beams from the headlamps so that they can be alternately flashed in sequence on opposite sides of the front of the vehicle as a warning signal.

(13) "Highway maintenance vehicle" means a vehicle used primarily or exclusively for road repair, maintenance, or related public works operations.

(14) "Industrial equipment" means any vehicle which is authorized to use amber lamps under WAC 204-21-130 for the purpose of landscaping, construction services, loading, digging, grounds keeping, and highway maintenance.

(((14)))(15) "Law enforcement agency" means any municipal, port district or tribal police department, county police department or sheriff's office, the Washington state patrol, or any other state or federal agency which is publicly authorized to carry out law enforcement duties which include the authority to stop and detain motor vehicles on the public highways of this state.

(((15)))(16) "Law enforcement vehicle" means a publicly owned or leased vehicle operated by a law enforcement agency and which is used for the law enforcement functions of the agency.

(((16) "Other construction and maintenance vehicle" means any vehicle owned or operated by a public agency or private company which is in the process of providing highway construction or maintenance services or is working in conjunction with any public utility.))

(17) "Oversize unit" means any vehicle towing a load that exceeds legal dimensions which may be equipped with flashing amber lights in addition to any other lights required by law.

(18) "Percent modulation" equals time-weighted power input with modulation to headlamp divided by time-weighted power input without modulation to headlamp times ((one hundred))100.

(19) "Pilot car" means any vehicle which is used to provide escort for overlegal size loads upon the roadways of this state.

(20) "Private carrier bus" means every motor vehicle designed for the purpose of carrying passengers (having a seating capacity for ((eleven))11 or more persons) used regularly to transport persons in furtherance of any organized agricultural, religious or charitable purpose. Such term does not include buses operated by common carriers under a franchise granted by any city or town or the Washington public utilities commission.

(21) "Public ((utilities))utility vehicle" means any vehicle used for construction, operations, ((and))or maintenance, and ((which))that is owned or operated by a public or private utility, including, but not limited to, companies providing water, electricity, natural gas, telephone, television cable services, and railroads, or that is working in conjunction with any public utility.

(22) "Rural newspaper carrier vehicle" means any vehicle driven on rural roads by carriers delivering newspapers on their route.

(23) "SAE" means the Society of Automotive Engineers. Copies of SAE Standards ((are available for review at the Washington State Patrol, P.O. Box 42600, Olympia, WA 98504-2600, and)) may ((also)) be ordered from the Society of Automotive Engineers International, 400 Commonwealth Drive, Warrendale, PA 15096-0001.

(24) "Search and rescue team vehicle" means any vehicle either publicly or privately owned which is used for responding to search and rescue situations.

(25) "Signal lamps" means red lamps mounted on the vehicle to be used in conjunction with the "stop signal" when the bus is loading or unloading passengers under certain conditions.

(26) "Snow removal vehicle" means any publicly or privately owned vehicle that is used primarily for removing snow and ice from roadways.

(27) "Tow truck" means any vehicle engaged in removing disabled or abandoned vehicles from the roadway and ((which))that is used primarily for that purpose.

(1) All emergency lamps must meet the criteria established in RCW 46.37.320. In descending order of preference, these are:

(a) Conformance to Federal Motor Vehicle Safety Standards, or; if none

(b) Conformance to current standards and specifications of the Society of Automotive Engineers, or; if none

(c) Certified for compliance by any recognized organization or agency such as, but not limited to, the American National Standards Institute, the Society of Automotive Engineers, or the American Association of Motor Vehicle Administrators.

(2) Headlamp flashing systems may be used for authorized emergency vehicles owned and operated by law enforcement agencies, licensed ambulance companies, and fire departments. Headlamp flashing systems must:

(a) Have a circuit that alternately flashes only the high beams from the headlamps at a rate of 60 to 120 flashes per minute per side.

(b) Be so designated that any failure to flash the lamps will not result in failure of the headlamp system to operate normally.

(c) Incorporate an override feature which must stop the flashing and provide full illumination from both high beam headlamps when the dimmer switch is in the high-beam mode.

(d) Have an indicator lamp included in the circuit to give a visible and unmistakable indication to the driver that the system is turned on.

(3) The following table outlines the color of emergency lamps to be used for each type of vehicle.

Vehicle Type	Lighting Required	Other Lighting Allowed
Authorized Emergency Vehicles (except Law Enforcement and Fire Department Vehicles)	1 red lamp	Flashing amber or white lamps
Law Enforcement Vehicles	1 blue lamp	Flashing red, amber, or white lamps
Fire Department Vehicles (RCW 46.37.184)	1 red lamp	Rear facing blue lamp Flashing amber or white lamps
Volunteer Firefighter Vehicles and Firefighter Private Vehicles (RCW 46.37.185)		If approved by the chief of their respective service, green lamps may be installed on the vehicle provided that the requirements outlined in subsection (4) of this section are met.
Public ((utilities))utility vehicles, ((other construction and))highway maintenance vehicles, snow removal vehicles, pilot cars, animal control vehicles, hazardous materials response team vehicles, search and rescue team vehicles, ((and)) rural newspaper carrier vehicles, and vehicles towing a load that exceeds legal dimensions.		One or more flashing amber lamps provided that the requirements of subsection (5) of this section are met.
Emergency tow trucks (WAC 204-21-020(8))	1 red lamp	One or more flashing amber and/or white lamps provided that the requirements of subsection (5) of this section are met. Rear facing blue lamps.
Snow removal vehicles that are owned or operated by a state, county, or municipal agency (WAC 204-21-020(26)) and highway maintenance vehicles (WAC 204-21-020(13)).		One or more flashing green and/or white lamps, provided that the requirements of WAC 204-21-170 are met.

(4) Green lamps for volunteer firefighter and firefighter private vehicles must:

(a) Meet the requirements of SAE J595 except that the color of the lamp must be green as the color described in SAE J578.

(b) Be visible for a distance of 200 feet under normal atmospheric conditions.

(d) Be mounted no less than 24 inches above the level surface upon which the vehicle stands, or may be placed on the forward portion of the top above the windshield.

(e) Be mounted anywhere from the center of the vehicle to the left side thereof.

(f) Be used only for the purpose of identification and the operator of a vehicle so equipped must not be entitled to any of the privileges provided in RCW 46.61.035 for the operators of authorized emergency vehicles.

(5) Amber lamps must:

(a) Be mounted and be of sufficient intensity so as to be clearly visible to approaching traffic for at least 500 feet in normal sunlight.

(b) Be mounted as outlined in WAC 204-21-020 and as follows:

(i) Must be mounted so that the entire projected area of the lens is visible from all eye heights of drivers of other vehicles at angles within 45 degrees left to 45 degrees right of the front of the vehicle. If the light within these required angles is blocked by the vehicle or any substantial object on it, an additional amber lamp must be displayed within the obstructed angle.

(ii) May be mounted at any height.

(c) Only be used on the vehicles described in subsection (3) of this section, when such vehicles are actually involved in construction, maintenance, or operations which require that warning be given to ensure the protection of the motoring public or the work crew. Lamps must not be illuminated while traveling to or from the site of operations. For the purposes of tow truck operations, the site of operations must be only that place where vehicles are attached to or detached from the tow truck. Lamps on pilot cars must be illuminated only while the vehicle is actually providing escort service. Lamps on rural newspaper delivery vehicles must only be illuminated when the vehicle is traveling on the delivery route. Lamps on oversize units may be illuminated when traveling on public roadways. The operator of these vehicles are not entitled to any other privileges provided in RCW 46.61.035 for the operators of authorized emergency vehicles.

(6) Three hundred sixty degree warning lamps must meet SAE Standard J845.

(7) Nothing in this section relieves the operator of any vehicle from displaying any other light or warning device required by statute or regulation.

(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))20 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) Snow removal vehicles owned or operated by state, county, or municipal agencies and highway maintenance vehicles may be equipped with flashing green and white lamps, in addition to amber lamps.

(a) The green and white lamps must be:

(i) Of sufficient intensity to be clearly visible to approaching traffic from a distance of at least 500 feet in normal sunlight; and

(ii) Must be mounted in accordance with WAC 204-21-020 and must be positioned so that the entire projected area of the lens is visible to drivers of other vehicles at all eye heights within an angle of 45 degrees to the left and 45 degrees to the right of the front of the vehicle. If the lamp is obstructed within these angles by the vehicle or any substantial component on it, an additional amber lamp must be displayed within the obstructed angle.

(b) The green and white lamps may only be illuminated while the vehicle is actively engaged in snow and ice removal or highway maintenance operations and must not be illuminated while the vehicle is traveling to or from the site of operations.

(c) The use of green and white lamps does not confer any privileges granted to authorized emergency vehicles as defined in RCW 46.61.035.

(5) 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))500 feet in normal sunlight, unless otherwise prescribed below.

(b) Have a minimum light intensity of the lamp filament not be less than ((twenty-one))21 candle power.

(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.

(1) The addition of a lamp, reflective device or other motor vehicle equipment must not impair the effectiveness of lighting equipment required by 49 C.F.R. Part 571.108, as it exists on February 22, 2022, or chapter 46.37 RCW.

(a) If a vehicle is in motion on a public roadway, the vehicle must not:

(i) Display aftermarket neon lighting devices.

(ii) Combine any type of letter, number, sign, symbol or combination thereof with an eye level brake light meeting the standards of 49 C.F.R. Part 571.108 (FMVSS 108). No function other than red reflex reflectors will be combined in eye level brake lights.

(iii) Have a lighted or electrically/mechanically powered sign or message board enabling change or movement of any displayed message to be displayed or affixed to the vehicle. Except:

(A) Vehicles that are used in conjunction with officially sanctioned or sponsored motor vehicle traffic control or movement may display lighted or electrically powered signs to assist in the efficient control of traffic movement on public roadways. The signs must be designed, worded, and located to limit misinterpretation and confusion by the motoring public.

(B) Electric signs may be unitized to identify taxicabs and the destinations of mass transportation vehicles. These signs must not contain any commercial or personal message and must be designed, worded, and located so that it is clearly differentiated from other required motor vehicle lights.

(b) If a vehicle is not in motion and parked on private property, the vehicle may use aftermarket lighting except as outlined under RCW 46.37.180.

(i) Be powered by an external source or in a manner which does not cause the required equipment on the vehicle to be out of compliance with 49 C.F.R. Part 571, chapter 46.37 RCW or Title 204 WAC.

(ii) Not be lit.

(iii) Not have continual motion.

(2) Pursuant to Title 49 C.F.R. Part 571.108, the addition of an aftermarket style ornament or other feature such as tinted plastic glass covers, a grille or slotted covers must not be placed in front of the headlamp lens, or in front of any other lighting devices installed on motor vehicles which impair the effectiveness of lighting equipment required under 49 C.F.R. Part 571.108 (FMVSS 108) or chapter 46.37 RCW. Except:

(a) Clear aftermarket headlamp covers.

(b) Headlamp wipers may be used in front of the lens provided that the headlamp system is designed to conform to all applicable photometric requirements in 49 C.F.R. Part 571.108 (FMVSS 108) with the wiper stopped in any position in front of the lens.

(c) A bike rack may be installed on the front of a municipal transit vehicle (as defined under RCW 46.04.355) provided that even with the bike rack installed, loaded or unloaded with bicycles, the headlight system still conforms with all applicable photometric requirements in 49 C.F.R. Part 571.108 (FMVSS 108).

(3) Red emergency lights are prohibited on any vehicle other than an authorized emergency vehicle, a law enforcement vehicle, an emergency tow truck as defined in WAC 204-21-020(8), school buses, and private carrier buses.

(4) Blue lights are prohibited on any vehicle other than a law enforcement vehicle as defined in WAC 204-21-020, a fire department vehicle as authorized in RCW 46.37.184, and an emergency tow truck as authorized in RCW 46.37.196.

(5) Flashing white lights are prohibited on any vehicle other than authorized emergency vehicles, law enforcement vehicles, school buses, and emergency tow trucks as defined in WAC 204-21-020.

(6) Green lamps are prohibited on any vehicle other than:

(a) A firefighter's private vehicle as authorized in RCW 46.37.185;

(b) A highway maintenance vehicle; and