Ohio Rules for Fog Lamps, Light Bars, Spotlights and Underglow

Start with the count, because Ohio regulates auxiliary lamps by type rather than as one undifferentiated group. R.C. 4513.12(A) permits any motor vehicle to carry not more than one spotlight and not more than three auxiliary driving lights mounted on the front, and it directs the director of public safety to prescribe the specifications. Ohio Adm.Code 4501-15-06 is that specification, and it breaks the three into a maximum of one auxiliary passing lamp under paragraph (B) and a maximum of two auxiliary driving lamps under paragraph (C). Paragraph (A) separately allows a maximum of two fog lamps. A build with two fog lamps, two driving lamps and one passing lamp is within both instruments; a five-pod light bar sold as five driving lamps is not.

Mounting height is where most aftermarket installations fail. Fog lamps must sit not less than 12 inches nor more than 30 inches above the level surface the vehicle stands on. Auxiliary passing lamps and auxiliary driving lamps must sit not less than 16 inches nor more than 42 inches above that surface. A light bar bolted to a roof rack or across the top of a windscreen is above 42 inches on any ordinary vehicle and therefore outside the rule regardless of how it is wired. Fog lamps also carry an aiming test in their own right: when the vehicle is loaded, none of the high-intensity portion of the light to the left of the centre of the vehicle may, at 25 feet ahead, project higher than four inches below the level of the centre of the lamp it comes from. Fog lamps meeting that standard may be used together with lower headlamp beams under paragraph (C)(2) of Ohio Adm.Code 4501-15-01.

R.C. 4513.17 then imposes two limits that apply on top of the equipment rules. Division (A) provides that where a vehicle with headlights also carries auxiliary lights, a spotlight or any other front light projecting a beam greater than 300 candlepower, no more than five such lights may be lit at any one time while the vehicle is on a highway. Because the two headlamps count toward that total, the practical ceiling is three extra high-output lamps burning together. Division (B) handles everything that is not a headlight, spotlight, signal light or auxiliary driving light: any such lamp projecting more than 300 candlepower must be aimed so that no part of the beam strikes the level of the roadway more than 75 feet from the vehicle. R.C. 4513.12(A) adds its own aim rule for the spotlight, which on approaching another vehicle must throw no part of its high-intensity portion to the left of the prolongation of the extreme left side of the vehicle, nor more than 100 feet ahead of it.

Colour and behaviour are policed separately, and this is the part Ohio treats most strictly. R.C. 4513.17(C)(1) prohibits flashing lights on motor vehicles altogether except to indicate a turn or in the presence of a vehicular traffic hazard requiring unusual care in approaching, overtaking or passing. The exceptions in (C)(2) are a closed list: emergency vehicles, road service vehicles towing or servicing a disabled vehicle, stationary waste collection vehicles actively collecting on the roadside, rural mail delivery vehicles, highway maintenance vehicles, farm machinery and its escorts, funeral hearses and escorts using purple or amber, and, since House Bill 33 of the 135th General Assembly took effect on October 3, 2023, emergency management agency vehicles displaying amber or red and white while marked with the agency's insignia. Division (D)(1) bars any private vehicle from displaying a flashing red, flashing red and white, or oscillating or rotating red light, and division (D)(2) reserves flashing or rotating blue, and blue and white, to a sworn law enforcement officer operating a public safety vehicle on duty. Division (E) preserves the use of hazard flashers on a disabled vehicle or in unfavourable atmospheric conditions.

Accent, ground effect and interior mood lighting fall under Ohio Adm.Code 4501-15-09, which is permissive but has a hard number in it. Accessory lamps are allowed provided their placement, installation or use does not interfere with or tend to confuse the required lamps, they may be used at any time, and they may not exceed 21 candlepower of intensity. Read together with R.C. 4513.17(D), that means white or amber underglow at low output is lawful in Ohio while anything red or blue is not, and anything that flashes falls foul of division (C)(1) whatever its colour. R.C. 4513.13(A) rounds out the side of the vehicle: cowl, fender and side lights must emit white or amber light without glare, and back-up lights, whether separate or combined with another lamp, may not be continuously lighted while the vehicle is moving forward. Headlamps themselves must match the colour requirements of Federal Motor Vehicle Safety Standard 108 at 49 C.F.R. 571.108, which R.C. 4513.19(B) adopts directly, so blue-tinted headlight bulbs are an offence in their own right.

Every one of these provisions carries the same criminal grade. R.C. 4513.12(B), 4513.13(B), 4513.17(F) and 4513.19(C) each make a violation a minor misdemeanor, which under R.C. 2929.28(A)(2)(a)(v) means a fine of not more than $150 and, under R.C. 2929.24, no jail term. A vehicle with a roof-mounted light bar, blue accent lighting and non-compliant headlight bulbs can therefore collect three separate minor misdemeanor citations from one stop rather than a single equipment charge.

The more practical consequence is the equipment order. R.C. 4513.02(F) allows an inspecting officer who finds a vehicle defective or in violation of Chapter 4513 to issue a repair order in the form the superintendent of the State Highway Patrol prescribes; the owner or operator must obtain the repairs and return the order with proof of compliance as directed. Under division (E), a vehicle found unsafe for operation may be ordered off the highway and not operated except for removal and repair. Division (B)(1) is the stop power behind this: when directed by a State Highway Patrol trooper, a driver must stop and submit the vehicle to an inspection covering brakes, lights, turn signals, steering, horns and warning devices, glass, mirrors, exhaust, wipers and tires.

Because Ohio has no periodic safety inspection for passenger cars, that roadside stop is the only routine check a private vehicle ever faces. The contrast inside the same chapter is stark: R.C. 4513.51 forbids operating a bus without a current State Highway Patrol safety inspection decal, R.C. 4513.52 requires those inspections at least annually with a fee of up to $200, and the registrar may not accept a bus registration application without a valid inspection report. No comparable scheme exists for cars, so an unlawful light bar in Ohio goes uncited until an officer sees it lit.