Truck Lighting Rules: Required Lamps and Reflectors (49 CFR 393)

Federal rules list the lamps and reflectors a commercial vehicle must have, by type of vehicle (49 CFR 393.11, Table 1). A tractor needs headlamps, three amber identification lamps, clearance and side marker lamps, tail and stop lamps, turn signals, hazard flashers and a backup lamp. A wide trailer needs red tail, stop and clearance lamps, three red identification lamps, side markers and reflectors. Every required lamp must work and must not be covered.

Facts checked October 22, 2026

Key Points

49 CFR 393.11 Table 1 lists the lamps, reflectors and their color, number and position by type of vehicle. A vehicle built on or after December 25, 1968 must meet FMVSS 108 as it stood when the vehicle was made (49 CFR 393.11(a))
Every required lamp must be capable of being operated at all times (49 CFR 393.9(a)). It may not be covered by the tailboard, any part of the load or its cover, dirt, or added equipment (393.9(b) and 392.33)
Front lamps are amber or white. Rear lamps are red, except rear turn signals and rear hazard flashers, which may be amber or red, and backup lamps, which are white (Table 1)
No commercial motor vehicle may have an amber stop lamp or tail lamp (49 CFR 393.11(c))
Exterior lamps must be steady-burning. The exceptions are turn signals, hazard flashers, school bus warning lamps, amber warning lamps on tow trucks and on vehicles hauling oversize loads, and warning lamps on emergency and service vehicles authorized by the State or local government (49 CFR 393.25(e))
Hazard flashers must work with the ignition off and make all required turn signals flash together (49 CFR 393.19)
Headlamps need an upper and lower beam that the driver can select. Extra driving lamps and fog lamps are allowed, but never in place of the required headlamps (49 CFR 393.24)
Since March 23, 2026, a truck tractor towing a trailer does not need a rear license plate lamp (91 FR 7871)

Required lamps and reflectors by vehicle type (49 CFR 393.11, Table 1)

	Number, color and place	Vehicles that need it
Headlamps	2 white, on the front, with upper and lower beams	Buses, trucks and truck tractors
Front turn signals	2 amber, at or near the front	Buses, trucks and truck tractors
Front identification lamps	3 amber, near the top and the center, 6 to 12 inches apart	Buses and trucks 80 inches or wider, and truck tractors
Rear identification lamps	3 red, near the top and the center, 6 to 12 inches apart	Buses and trucks 80 inches or wider, trailers 80 inches or wider, and pole trailers
Front clearance lamps	2 amber, one on each side, as high as practicable, to show the overall width	Buses and trucks 80 inches or wider, truck tractors, trailers 80 inches or wider, pole trailers and projecting loads
Rear clearance lamps	2 red, one on each side, as high as practicable, to show the overall width	Buses and trucks 80 inches or wider, trailers 80 inches or wider, pole trailers and projecting loads
Tail lamps	2 red, on the rear, 15 to 72 inches above the road	Every type in the table
Stop lamps	2 red, on the rear, lit when the service brakes are applied	Every type except projecting loads
Side marker lamps	Amber near the front of each side and red near the rear of each side. Amber ones are also needed in the middle of each side when the vehicle is over 30 feet long	Buses and trucks, and trailers. Truck tractors need the front amber ones only
Reflex reflectors	Red on the rear. Red near the rear of each side. Amber near the front of each side, and amber in the middle of each side when the vehicle is over 30 feet long	Rear: every type except projecting loads. Side reflectors vary by type
Rear turn signals	2 amber or red, on the rear	Every type except projecting loads
Hazard flashers	2 amber on the front and 2 amber or red on the rear	Front: buses, trucks and truck tractors. Rear: every type except projecting loads
Backup lamp	1 or 2 white, on the rear, lit when the vehicle is in reverse	Buses, trucks and truck tractors
License plate lamp	1 white, lighting the rear plate whenever the headlamps are on	Buses, trucks, truck tractors and trailers. Not needed on a tractor towing a trailer

What lights does a semi truck need?

A truck tractor needs two white headlamps and two amber front turn signals. It needs three amber identification lamps at the top of the cab. It needs two amber clearance lamps at the front and amber side marker lamps and amber side reflectors near the front. At the rear it needs two red tail lamps, two red stop lamps, two red or amber turn signals and two red reflectors. It also needs hazard flashers on the front and rear and a white backup lamp (49 CFR 393.11, Table 1). A tractor that is towing a trailer does not need a rear license plate lamp. FMCSA added that exception in a final rule effective March 23, 2026 (91 FR 7871).

What lights does a trailer need?

A semitrailer or full trailer that is 80 inches or wider needs two red tail lamps, two red stop lamps and two red or amber turn signals. It needs two amber clearance lamps at the front and two red ones at the rear. It needs three red identification lamps at the rear. It needs amber side marker lamps near the front, red ones near the rear, and amber ones in the middle of each side if the trailer is over 30 feet long. It also needs a red reflector on the rear, red and amber side reflectors, and a license plate lamp (49 CFR 393.11, Table 1). A trailer built on or after March 1, 1979 must have its rear side marker lamps 15 to 60 inches above the road (Table 1, footnote 4). Many trailers this wide also need reflective tape. See our trailer reflective tape guide.

What are the orange lights on top of a truck called?

The three amber lamps in a row at the top of a tractor's cab are identification lamps. They are required on buses and trucks 80 inches or wider and on truck tractors, with their centers 6 to 12 inches apart (49 CFR 393.11, Table 1). Clearance lamps are the amber lamps at the upper front corners and the red lamps at the upper rear corners. They show how wide the vehicle is. The side marker lamps are the smaller amber and red lamps along the sides.

Why do trucks have clearance lights?

Clearance lamps show the overall width of the vehicle to other drivers. Table 1 says one lamp goes on each side of the vertical centerline to indicate overall width, as high as practicable. The rule allows some changes when needed. A tractor's clearance lamps may be placed to show the width of the cab instead of the vehicle. A trailer's front clearance lamps may be mounted lower if mounting them at the top would not mark the full width (Table 1, footnote 15).

Can I drive with a light out or covered?

No. Every required lamp must be capable of being operated at all times (49 CFR 393.9(a)). The rules also bar driving a commercial motor vehicle when a required lamp or reflector is covered by the tailboard, any part of the load or its cover, dirt, or added equipment (49 CFR 392.33 and 393.9(b)). A dirty or blocked lamp is a violation too. Either one can be cited at a roadside inspection. Whether a given defect puts the truck out of service is set by the CVSA out-of-service criteria, which we do not reproduce here. Check your lamps in the pre-trip inspection.

Can I add LED bars, fog lamps, strobes or colored lights?

Part 393 does not name a bulb type. It sets the color, number, position and performance of the required lamps, and it says required lamps on vehicles built after December 25, 1968 must meet FMVSS 108 (49 CFR 393.11(a) and 393.25(c)). Extra auxiliary driving lamps and front fog lamps are allowed in addition to the required headlamps. They must be aimable, mounted so the aim does not shift, and aimed to the standards (393.24(b) to (d)). All exterior lamps must be steady-burning, with only the exceptions listed in 393.25(e). Added equipment may not cover a required lamp (393.9(b)). This page covers the federal rules only. States have their own rules on extra lights and colors, so check yours.

What are the rules on hazard flashers and combined lamps?

Hazard flashers must work independently of the ignition and make all required turn signals flash together (49 CFR 393.19). A driver whose vehicle stops on the road or shoulder for any reason other than a necessary traffic stop must turn the flashers on at once and leave them on until the warning devices are out (49 CFR 392.22(a)). Lamps may be combined in one housing if each still works as required. A turn signal may not be combined with a brighter lamp, and it may not be combined with a stop lamp unless the stop function is off while the turn signal is on. A clearance lamp may not be combined with a tail lamp or identification lamp (49 CFR 393.22). Stop lamps must light when the service brakes are applied (49 CFR 393.25(f)).

What lamps does a load that sticks out need?

A load that sticks out needs its own lamps when the vehicle runs during the hours when headlamps are required. If a load extends more than 4 inches past the side of the vehicle, the outer front edge needs an amber lamp and the outer rear edge needs a red lamp. A load that extends more than 4 feet past the rear needs a red side marker lamp on each side and two red lamps and two red reflectors on the rear (49 CFR 393.11, Table 1, footnotes 9 and 10). Battery-powered lamps are allowed on projecting loads only (49 CFR 393.23).

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Frequently Asked Questions

What lights are required on a semi truck?+

A truck tractor needs two white headlamps, two amber front turn signals and three amber identification lamps. It needs amber clearance lamps and side markers at the front. At the rear it needs red tail and stop lamps, turn signals and reflectors. It also needs hazard flashers and a white backup lamp (49 CFR 393.11, Table 1).

Are clearance lights required on a trailer?+

Yes, on a semitrailer or full trailer 80 inches or wider. It needs two amber clearance lamps at the front and two red ones at the rear to show its overall width, plus three red identification lamps at the rear (49 CFR 393.11, Table 1). Trailers under 80 inches wide are not required to have clearance lamps.

What are the orange lights on trucks called?+

The row of three amber lamps at the top of the cab is the identification lamps. The amber lamps at the upper front corners are clearance lamps, and the smaller amber lamps along the sides are side marker lamps (49 CFR 393.11).

Why do trucks have clearance lights?+

To show the width of the vehicle to other drivers. Table 1 of 49 CFR 393.11 puts one on each side, as high as practicable, to indicate the overall width.

Is it illegal to drive a truck with a light out?+

A required lamp must be capable of operating at all times, and it must not be covered by the load, dirt or added equipment (49 CFR 393.9 and 392.33). A lamp that is out can be cited at a roadside inspection. Fix it before you run.

Do I need a license plate light on a tractor?+

Not when the tractor is towing a trailer. FMCSA's final rule effective March 23, 2026 removed that requirement (91 FR 7871). A trailer still needs a lamp lighting its own rear plate, and a tractor with no trailer attached needs one if it displays a rear plate.

Can a truck have flashing or strobe lights?+

Only the kinds listed in 49 CFR 393.25(e). Exterior lamps must be steady-burning, except turn signals, hazard flashers, school bus warning lamps, amber warning lamps on tow trucks and on vehicles hauling oversize loads, and warning lamps on emergency and service vehicles authorized by the State or local government. State law may add more limits.

Can I put LED lights on my truck?+

Part 393 does not name a bulb type. The required lamps must be in the right color, number and position, and must meet FMVSS 108 (49 CFR 393.11 and 393.25). Extra auxiliary driving lamps and fog lamps are allowed in addition to the required ones (393.24). Check your state's rules on extra lights too.

Can a truck have amber brake lights?+

No. No commercial motor vehicle may have an amber stop lamp or tail lamp, or any lamp combined with one (49 CFR 393.11(c)). Stop and tail lamps must be red.

Do hazard lights have to work with the key off?+

Yes. The hazard warning signal must work independently of the ignition switch and make all required turn signals flash at the same time (49 CFR 393.19).

More federal trucking rules

Related terms and pages

Sources

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This is a plain-language summary for reference, not legal advice. Check the official rule text before you rely on any detail. Ask a compliance professional about your own operation.