Montana Caps Extra Lamps at Two Each and Bans Flashing Underglow

Montana's added-lighting rules sit in Title 61, chapter 9, part 2, and they are written as counts and heights rather than as a general reasonableness test. Section 61-9-217(1), MCA, allows a motor vehicle no more than two spot lamps, and requires a lighted spot lamp to be turned off on approaching another moving vehicle from either direction. Section 61-9-217(2) allows no more than two fog lamps producing a low, wide-angle pattern to increase short-range visibility, which must be mounted on the front not more than 30 inches above the level surface the vehicle stands on and aimed so that, with the vehicle unloaded, none of the high-intensity portion of the light to the left of the vehicle centre projects, at 25 feet ahead, higher than 4 inches below the level of the centre of the lamp it comes from. Fog lamps meeting that subsection may be used with lower headlamp beams under 61-9-220(2), and a fog lamp may not substitute for headlamps.

Section 61-9-217(3) covers the long-range pencil beam. A vehicle may carry no more than two auxiliary driving lamps used to supplement the upper beams, mounted on the front not less than 16 inches and not more than 42 inches above the level surface the vehicle stands on. They may not substitute for headlamps and may not be lit at any time the headlamps are required to be on low beam. Subsection (4) then deals with the light bar problem directly: an auxiliary off-road lamp mounted more than 42 inches above the level surface may not be lighted while the vehicle is operated or parked on a highway. A roof-mounted bar on a pickup is therefore lawful to carry and unlawful to switch on, even at the kerb.

Section 61-9-225(2), MCA, sets the aggregate limit. Where a vehicle equipped with the required headlamps also carries auxiliary lamps, a spot lamp or any other front lamp projecting a beam of more than 300 candlepower, no more than four such lamps in total may be lit at any one time on the front of the vehicle while on a highway.

The prohibitions are in 61-9-226, which the 2025 Legislature amended by Chapter 343. Subsection (1) requires that any lighted lamp or illuminating device other than headlamps, spot lamps, auxiliary lamps, flashing turn signals, emergency vehicle warning lamps and school bus warning lamps, if it projects more than 300 candlepower, be directed so that the high-intensity portion of the beam does not strike the roadway more than 75 feet ahead of the vehicle. Subsection (2)(a) prohibits a lamp or device displaying a red light visible from in front of the centre of the vehicle unless a red light visible from the front is expressly authorized or required elsewhere in the code. Subsection (2)(b), the 2025 addition, prohibits green lights that are flashing, rotational or continuous, except on vehicles the chapter authorizes, including snow-removal equipment operated by the Department of Transportation or another government entity and a police or authorized emergency vehicle serving as an on-scene incident command or control vehicle. Subsection (3) prohibits flashing, blinking, sequential, rotating or pulsating lights except on authorized vehicles or as a turn indicator or hazard warning. Subsection (4) reaches decoration: aftermarket license plate lighting that is not original manufacturer's equipment, and undercarriage decorative lighting that rotates, flashes or oscillates or displays a color the chapter authorizes for police and emergency vehicles, may not be illuminated on a vehicle operated on a highway or street. Steady, non-police-colored underglow that neither flashes nor rotates is not caught by subsection (4).

A few permissive allowances sit alongside. Section 61-9-219, MCA, allows up to two side cowl or fender lamps emitting amber or white light without glare, one running board courtesy lamp on each side in white or amber without glare, and up to two backup lamps that must not be lit while the vehicle is moving forward. Section 61-9-219(4) permits hazard warning lamps: forward-facing lamps mounted at the same level and as widely spaced laterally as practicable showing simultaneously flashing white or amber, rear-facing lamps showing simultaneously flashing amber or red, all visible from at least 500 feet at night under normal atmospheric conditions. Section 61-9-227 lets firefighters authorized by their chief, and search and rescue and volunteer emergency medical personnel authorized by the county sheriff, run a blinker-type or revolving red light on the front or top of a privately owned vehicle while responding to, but not returning from, an emergency, and requires the driver to carry an identification card naming the owner and the organization and bearing the signature of the person who authorized the use.

Section 61-9-109(1), MCA, makes it a misdemeanor to drive or permit to be driven on a highway a vehicle that is not equipped with lamps and other equipment as chapter 9 requires or that is equipped in a manner that violates the chapter, and 61-9-109(5) requires all lamps and equipment the chapter requires to be maintained in proper working order and adjustment at all times. Where no other penalty is provided, 61-9-511(2) sets the fine at not less than $10 and not more than $100 for a first conviction, not less than $25 and not more than $200 for a second conviction within one year, and not less than $50 and not more than $500 for a third or subsequent conviction within one year of the first.

Section 61-9-511(3) treats failure to pay as civil contempt, allowing the court to order execution under 25-13-204 and Title 25, chapter 13, or to order community service where the person cannot pay, and 61-9-511(4) allows county jail at the incarceration credit rate in 46-18-403 where no property is found and community service is found inappropriate. Enforcement is roadside: 61-9-501(1) lets the department or its agents require a driver to stop and submit to an inspection on reasonable cause to believe the vehicle is unsafe or not equipped as required by law, and 61-9-501(3) requires a written notice specifying the deficiencies and giving 5 days to put the vehicle right.