Iowa Caps Auxiliary Lamps at Three and Bans Blue Light

Iowa's add-on lighting rules are spread across six short sections of chapter 321, and each one contributes a hard figure. Section 321.403 says any motor vehicle may be equipped with not to exceed three auxiliary driving lamps mounted on the front at a height not less than twelve inches nor more than forty-two inches above the level surface upon which the vehicle stands, and requires them to meet the rest of the chapter's limits. Section 321.402 permits not more than one spot lamp, and requires every lighted spot lamp to be aimed and used on approaching another vehicle so that no part of the high-intensity portion of the beam is directed to the left of the prolongation of the extreme left side of the vehicle, nor more than one hundred feet ahead of it.

Section 321.420 is the count that catches light bars. Where a vehicle equipped with the headlamps required by the chapter also carries any auxiliary lamps, a spot lamp, or any other lamp on the front projecting a beam of intensity greater than three hundred candlepower, not more than four of those lamps may be lighted at any one time when on a highway. Section 321.421(1) then aims everything that is not a headlamp, spot lamp or auxiliary driving lamp: any lighted lamp or illuminating device over three hundred candlepower must be directed so that no part of the beam strikes the roadway at a distance of more than seventy-five feet from the vehicle. Section 321.421(2) makes a violation a simple misdemeanor punishable as a scheduled violation.

Color is governed separately and tightly. Section 321.422(1) forbids driving or moving any vehicle or equipment on a highway with any lamp or device displaying or reflecting a red light visible from directly in front, and forbids displaying any color of light other than red on the rear, except that stop lights and directional signals may be red, yellow, or amber. That single sentence disposes of most rear-facing accent lighting: a white, blue or green glow visible from behind is not permitted, and a forward-facing red one is not either.

Flashing is prohibited outright unless it is on the list. Section 321.423(2) states that a flashing light on or in a motor vehicle is prohibited except in ten enumerated cases, and the list is one of specific vehicles and specific functions rather than a general allowance: an authorized emergency vehicle, a turn, mechanical failure or emergency stop signal, a rural mail carrier's roof dome light in a shade between white and amber, a vehicle under an excess size permit issued under chapter 321E, permitted blue and white lights, school bus warning lights under sections 321.372 and 321.373, amber lights on towing, recovery, utility, municipal, highway maintenance, construction and waste collection vehicles, modulating motorcycle headlamps conforming to the federal standard, and a funeral procession escort vehicle under section 321.324A.

Blue is the strictest color of all. Section 321.423(3)(a) says a blue light shall not be used on any vehicle except a vehicle owned or exclusively operated by a fire department, a member's own vehicle authorized by the fire chief after emergency vehicle operations training, an EMS member's vehicle authorized by the chief officer of the agency, an authorized emergency vehicle, and state or local snow equipment where the blue is rear-facing and used with amber and white while treating or removing snow and ice. Paragraph (b) adds that a person shall not use only a blue light unless the vehicle qualifies under the fire or EMS categories, and section 321.423(4) expires any authorization at midnight on December 31 five years after issue, or sooner if the vehicle changes hands or the member leaves the service.

One related rule catches tinted lamp covers rather than added lamps. Section 321.404A prohibits operating a motor vehicle, motorcycle or motorized bicycle equipped with a device that restricts the light output of a headlamp required under section 321.385 or 321.386, a rear lamp required under section 321.387, a signal lamp or signal device required under section 321.404, or a directional signal device described in section 321.317.

8A, subsection 3, so they are charged by citation in lieu of arrest with fixed amounts rather than by discretionary fine. 423. 1(1)(a) carries a fine of $105 to $855 and possible jail of up to 30 days if it is prosecuted rather than scheduled. 4(11) paragraphs a, b, c and h conduct spot inspections wherever they have reasonable grounds to believe equipment violations exist. 423(5), and may be revoked by the fire chief or the department if the light is used beyond its authorized scope.