Minnesota Auxiliary Lights: Two Each, Height Limits, Four Lit at Once

Each auxiliary lamp type in Minn. Stat. 169.56 has its own number and its own mounting band, measured from the level surface on which the vehicle stands. Spot lamps under subd. 1 are limited to two and must be aimed and used, when approaching another vehicle, so that no part of the high-intensity portion of the beam falls on the road surface to the left of the vehicle's center or more than 100 feet ahead. Fog lamps under subd. 2 are limited to two mounted on the front between 12 and 30 inches high, aimed so that with the vehicle unloaded no high-intensity light to the left of center projects, at 25 feet ahead, higher than four inches below the center of the lamp; fog lamps meeting that test may be run with lower headlamp beams. Auxiliary low-beam lamps under subd. 3 are limited to two mounted between 24 and 42 inches. Auxiliary driving lamps under subd. 4 are limited to two mounted between 16 and 42 inches. The last two both fall under Minn. Stat. 169.60, which requires selectable beams revealing persons and vehicles at 350 feet on the upper distribution and 100 feet on the lower, with the low beam aimed so its high-intensity portion does not strike an approaching driver's eyes.

The height limits are not advisory and Minnesota gives them a specific remedy. Under Minn. Stat. 169.56, subd. 5(b), no vehicle may be operated on a public highway unless the auxiliary lamps permitted in subds. 3 and 4 comply with the height requirements or are completely covered with an opaque material. A light bar mounted on a roof or a bumper outside the 16-to-42-inch band is therefore lawful to carry only if it is physically covered, not merely wired off. The one exemption is for snow work: subd. 5(a) lets the auxiliary low-beam lamps of subd. 3 sit above 42 inches on a truck whose required headlights are obstructed by a snowplow blade, and forbids illuminating them when no blade is mounted.

Count matters as much as height. Minn. Stat. 169.63(b) provides that where a vehicle with the required headlamps also carries auxiliary lamps, spot lamps or any other front lamps projecting a beam greater than 300 candlepower, not more than four such lamps may be lit at any one time on a highway. Paragraph (c) leaves the maximum beam candlepower of any combination used for road lighting to the commissioner of public safety. Under Minn. Stat. 169.64, subd. 1, any lighted lamp on the vehicle other than a headlamp, spot lamp or auxiliary driving lamp that projects more than 300 candlepower must be directed so that no part of its beam strikes the roadway more than 75 feet from the vehicle, which is what constrains work lamps, rock lights and scene lighting.

Colour is where Minnesota is strict. Minn. Stat. 169.64, subd. 2(a) prohibits equipping or driving any vehicle with a lamp or device displaying a red light or any colored light other than those required or permitted by chapter 169, unless the commissioner of public safety authorizes it. Subd. 4(a) bans blue lights on all vehicles except road maintenance and snow removal equipment operated by or under contract to the state or a political subdivision; the only consumer openings are a blue light of up to one-inch diameter as part of a motorcycle's rear brake light under subd. 4(c), and the same one-inch allowance for a collector vehicle under subd. 4(d). Subd. 4a makes it unlawful to project a white light at the rear of a vehicle while travelling, except for reversing, licence plate illumination under Minn. Stat. 169.50, subd. 2, authorized strobes, and the enumerated warning uses. Subd. 3(a) prohibits flashing lights except on the listed vehicle classes and for turn signals and hazard warning. Together those rules leave no room for aftermarket underglow, colour-changing grille lights or rear-facing white bars on a passenger car.

Motorcycles are the exception the Legislature actually wrote. Minn. Stat. 169.56, subd. 6, added by Laws 2024, chapter 104, article 1, section 39, allows a motorcycle to carry white ground lights mounted underneath, notwithstanding the white-light rule in 169.64, subd. 4a, provided the bulbs or strips are not visible to operators of other vehicles and the lights are aimed to project a steady, nonflashing beam of no more than six feet in radius directly onto the roadway around the machine. Nothing equivalent exists for cars or trucks.

Two further Minnesota requirements catch cheap parts. Minn. Stat. 169.64, subd. 10 makes it unlawful to equip or operate a vehicle with any material covering a headlamp, tail lamp or reflector, with only three exceptions: manufacturer's original equipment, material that is clear and colorless, and the opaque covering that Minn. Stat. 169.56 requires for out-of-height auxiliary lights. Smoked headlight and tail light covers therefore fail. And under Minn. Stat. 169.65(b) no one may sell or use a headlamp, auxiliary driving lamp, rear lamp, signal lamp, spot lamp, clearance lamp, marker lamp or reflector unless the type has been submitted to and approved by the commissioner of public safety, with paragraph (c) requiring the approved lamp to bear a permanently marked trademark or name and model designation legible when installed.

Lighting offences under chapter 169 carry no penalty of their own, so Minn. Stat. 89, subd. 1 supplies one: a petty misdemeanor, punishable under subd. 2 by a fine of not more than $300 with no jury trial and no imprisonment. It becomes a misdemeanor where the violation is committed in a manner or under circumstances likely to endanger a person or property, which is the natural charge for glare-producing lamps aimed at oncoming traffic, or where the driver has two or more petty misdemeanor convictions under the chapter within the preceding 12 months.

Minn. Stat. 47, subd. 1(a) separately makes it unlawful for a driver, and for an owner who causes or knowingly permits the driving, to operate a vehicle that is not equipped with lamps and other equipment in proper condition and adjustment as required by the chapter, or that is equipped in any manner in violation of it, so the registered owner can be reached for a light bar an employee or family member was using. Minnesota has no periodic passenger-vehicle safety inspection, so this is enforced at the roadside: Minn.

Stat. 771 establishes a State Patrol spot-check inspection program for unsafe vehicles and equipment, and subd. 4 provides that use of the state's highways and streets constitutes consent to those inspections. Selling a lamp type the commissioner of public safety has not approved is its own violation under Minn. Stat. 65(b).