Correct light placement on trucks starts with mandatory lamp locations and mounting heights, which set the baseline for every other decision. Auxiliary and work lights go on after that baseline, positioned so they never obstruct a required lamp and aimed so they do not glare oncoming traffic. Daily inspection confirms the setup still meets Standard 13 before the truck leaves the yard.
TL;DR:
- Mandatory lamps must be mounted within specified height ranges, with auxiliary and work lights positioned so they do not obstruct required signals or cause glare.
- Most lamps are placed between 380 and 1,830 millimeters from the ground, depending on their function, with rear signals sometimes permitted higher.
- Auxiliary lights should be mounted on the roof, bumper, or inside the cargo area with aim and height carefully controlled to avoid glare and ensure legality.
- Daily inspections must verify all signal lamps are operational, properly mounted, clean, and correctly functioning to meet safety standards.
- Certification details for light fixtures are product-specific; verify SKU certification, permitted colors, and vehicle compatibility before installation or purchase.
Regulated lamp types and canonical mounting height rules
Every truck carries a set of lamps and reflectors that federal rules consider mandatory, each with a defined job: headlamps and daytime running lamps for forward visibility, tail, stop and turn lamps for rear signalling, clearance and identification lamps for marking vehicle width and presence, side markers and reflex reflectors for lateral visibility, plus licence plate and backup lamps. Transport Canada’s lighting location requirements set the mounting ranges for these lamps.
- Side markers and reflex reflectors generally mount between 380 and 1,530 millimetres from the ground, per Transport Canada’s height ranges.
- Tail and stop lamps sit within a 380 to 1,830 millimetre range, with rear turn signals permitted up to 2,110 millimetres where specified, according to the same Transport Canada guidance.
- Headlamps mount within prescribed height ranges, and clearance or identification lamps are generally positioned as high as practicable on the cab or body.
- Lamps must be permanently attached, and their faces must be perpendicular or parallel to the vehicle’s centreline unless the device carries photometric certification for an angled mount, as described in Canada Motor Vehicle Safety Standard 108.
- Loads overhanging the rear by more than 1.5 metres require a red light during poor visibility, or a red flag at other times, under Ontario’s truck handbook rules.
Fleet managers who want a single compliance reference for their vocational trucks can start with our fleet lighting compliance guide, which walks through these ranges in more detail.
Common lamp types and where they typically sit
Mapping these categories onto an actual vehicle makes the height rules concrete. Front lighting carries the heaviest regulatory load: headlamps and daytime running lamps for forward illumination, parking lamps for low-light standing, and front clearance or identification lamps mounted as high as practicable on cab-over or wide-body trucks.
Rear lighting covers the signalling functions drivers behind the truck depend on.
- Tail, stop and turn lamps mount within the 380 to 1,830 millimetre range noted above, with turn signals sometimes permitted higher.
- Licence plate lamps illuminate the plate without shining into following traffic.
- Backup lamps face rearward and typically activate with reverse gear.
- Rear clearance and identification lamps mount near the top of the body on wider trucks and trailers.
Side and intermediate markers fill the gaps along a long wheelbase, and reflex reflectors back them up when the vehicle is unlit. Longer or wider trucks need additional intermediate markers so no stretch of the body goes unmarked. Marker lamp codes such as P2, P3 and A refer to photometric performance classes rather than colour or position, so installers should check the specific code a lamp carries against the mounting location it is meant for, not assume interchangeability.
Placement and aiming guidance for auxiliary and work lights
Auxiliary lighting, including LED light bars, cube lights, scene lights and cargo lamps, goes on after the mandatory lamps are accounted for, not instead of them; it is important to consider moving truck parking in Canada: how to reserve curb space when planning auxiliary lighting and setting up staging areas safely. The goal is added illumination without blocking a required lamp’s line of sight or creating glare for other drivers.
- Mount scene and work lights on the roof rack or rear of the cab, where they illuminate the work area without sitting in front of tail or clearance lamps.
- Mount driving lights on the bumper or grille, low enough that their beam pattern stays below the sightline of oncoming headlamps.
- Mount cargo lighting inside the bed or cargo area, aimed downward rather than outward, so it lights the work zone instead of the roadway.
- Check that every auxiliary lamp placement still leaves OEM clearance, marker and identification lamps fully visible from the angles those lamps are meant to be seen from.
Pro Tip: Aim scene lights for a wide, close work-area pattern rather than a long throw; a driving-style beam in a scene-light position is a common source of glare complaints during roadside work.
Permanent, bolted mounts hold up better during trip inspections than suction-cup or clamp-style temporary fixtures, which loosen with vibration and often fail a roadside check. Where an auxiliary device also performs a safety or signalling function, treat its placement and aiming requirements the same way you would an OEM lamp, and confirm the certification notes on the product page before finalizing a mounting location.
Mounting best practices and avoiding glare
A rigid, permanent mounting point matters as much as the lamp itself. Avoid mounting on removable panels, tailgates that flex, or glazing, since movement changes aim over time and can eventually break the mount.
- Keep lamp faces perpendicular to the centreline at the front and rear, and parallel to it along the sides, unless the device is photometrically certified for an angled install, per Canada Motor Vehicle Safety Standard 108.
- Leave clearance for lens replacement and routine cleaning without removing the whole fixture.
- If a mounting position creates glare risk for oncoming or following traffic, lower the mounting height, add a shield, or switch to optics suited to a work pattern rather than a driving pattern.
- A lifted suspension can push lamps above their allowable height range, which may call for re-aiming or relocating the fixture, as noted in CCMTA’s excessively raised vehicles guidance.
Our guide on improving roadside visibility covers beam-pattern selection for common work scenarios in more detail.
Daily checks and trip-inspection implications for lighting
A short daily check catches most lighting defects before they become an out-of-service issue. Confirm every lamp is present, securely mounted, has a clear lens, shows the correct colour, and that turn, stop and tail functions all respond when tested.
- Walk the vehicle and test every signal and marker lamp with the engine running.
- Note any cracked, fogged or missing lens and schedule a replacement before the next trip.
- Flag major defects immediately: NSC Standard 13 treats failure of both rearmost tail lamps, both rearmost brake lamps, or a rearmost turn-indicator lamp as conditions that prohibit operation.
- Keep photometric certification or installation test records on hand for any angled or non-standard mount.
- Repair visibility and signalling defects before anything else when returning a vehicle to service.
Where to find certification details for specific lights
An example supplier stocks inventory locally and ships across the country, and each product page lists the certification, permitted colours and vehicle compatibility specific to that SKU. Generalizing a certification or colour claim across the catalogue is not reliable: confirm it on the individual product page rather than assuming it carries over from a similar item.
Light up your fleet with the right fixtures for the job
Once the mandatory lamp locations are locked in, the right auxiliary fixture depends on where the work actually happens on the truck. The 15" Cargo Light suits bed and cargo illumination, lighting the load area without throwing glare at following traffic. The Fleet Beam 120, an LED Work Light Combo Beam, handles scene and work lighting where a wider, closer pattern is needed. The Fleet SM Stealth, a Smoked Lens Surface Mount, gives a low-profile option where a flush, discreet fixture fits the install better than a raised housing.
Each product page lists the SKU-specific certification, permitted colours and vehicle compatibility, so check the listing before you order. The full catalogue, including the SMR Patrol Line, SMR Fleet Line, SMR Signal Line and other product lines, is available through our collections page, with Ottawa stock and shipping across the country.
FAQ
What are the lights underneath a truck called?
Lights mounted low on a truck’s body are typically clearance lamps, side marker lamps or reflex reflectors, depending on their function and colour. These sit within the height ranges set by Transport Canada’s lighting location rules and mark the vehicle’s width and length for other drivers.
What are the different types of truck lights?
A truck’s mandatory lighting set generally includes headlamps, tail and stop lamps, turn signals, clearance lamps, identification lamps, side markers, reflex reflectors, licence plate lamps and backup lamps. Auxiliary categories added on top of that set include work lights, scene lights and cargo lights, each serving a function beyond the mandatory requirement.
Which lights are positioned where on a truck?
Headlamps and front clearance or identification lamps sit at the front, tail, stop, turn, backup and licence plate lamps sit at the rear, and side markers with reflex reflectors run along the length of the body. The specific mounting heights for each category come from Transport Canada’s federal location requirements.
Why do some trucks have lights on top of the cab?
Roof-mounted lamps on wider or taller trucks usually serve as identification or clearance lamps, mounted as high as practicable so other drivers can judge the vehicle’s height and width from a distance. Some fleets also mount auxiliary scene or work lighting on the roof rack, positioned so it does not block those mandatory lamps.
When does an overhanging load need a marker light?
A load that extends more than 1.5 metres past the rear of the vehicle requires marking, with a red light required during periods of poor visibility and a red flag or marker acceptable otherwise. This threshold and the marking rule come from Ontario’s truck handbook.
