Western Australia
This is not legal advice, and it was not written or reviewed by a lawyer. It is our reading of publicly available legislation and government guidance, done by engineers, and it may be wrong or out of date.
Nothing on this page has been confirmed. Treat it as a pointer to the source material rather than an answer.
Road rules change, they differ between states, and an officer at the roadside is not bound by anything we have written. Where we cite legislation, follow the link and read it — that is what governs you. For anything you intend to rely on, ask your state’s transport authority or a lawyer.
Fitted on a road vehicle
Conditional
Allowed only if the lamps never flash, and cannot be seen by other motorists whether the vehicle is moving or parked.
Operating while driving
Conditional
Allowed only if the lamps never flash, and cannot be seen by other motorists. Light reflecting off chromed underbody parts counts as being seen.
Car parks and other road related areas
The condition is written as visible to other motorists rather than as being on a road, so it may apply in a car park too. Not confirmed.
Where you can use it
Vehicle standards govern vehicles used on roads. A vehicle that is not on one is outside them.
Not visible to other motorists
This jurisdiction's own guidance accepts under-body lighting provided it does not flash and cannot be seen by other motorists, moving or parked.
But: Stricter than it sounds. A driver in a low car seeing the lamps, or light reflecting off chromed underbody parts, is expressly given as grounds for a defect notice.
Show cars and display vehicles
A vehicle that is not used on a public road is outside these rules. Any colour, any pattern, any brightness.
But: The moment it is driven on a public road it is a road vehicle again, and everything on this page applies to it.
Transported on a trailer
A car being carried is a load, not a vehicle in use, so it does not have to comply while it is on the trailer. This is how a show car reaches a show with the lighting fitted.
But: The trailer and the towing vehicle still have to comply. Switching the lighting on during transport is a separate question — a lit load on a public road can still be caught by what the combination shows. Run it at the venue.
Private property
Driveways, private land, workshops and car parks that are not open to the public are not roads or road related areas.
But: Many car parks that feel private are road related areas in law. If the public can drive in, assume the road rules reach it.
Off-road and private land
Paddocks, private tracks, farms and 4WD parks are not public roads or road related areas.
But: Getting there is usually road use. National parks and reserves have their own rules, and some tracks within them are gazetted roads.
Race circuits and track days
A closed circuit is not a public road, so vehicle standards do not reach it. The circuit's own rules apply instead, and at a sanctioned event so do the sanctioning body's technical regulations. A scrutineer can require lighting to be removed or disabled.
But: Red facing rearward means something specific on a circuit. Rain lights — a red rear lamp within 100 mm of the centreline — have been mandatory at Motorsport Australia race events since 2020 and must be an FIA or CIK approved unit. Approval attaches to the device rather than to the light it emits, so configuring this product to look like a rain light does not make it one. It will fail scrutineering, and until it is checked it tells drivers behind you something untrue. Fit a real one.
Stationary at a show, on display
Parked at a venue with the bonnet up, doors open, engine bay and cabin lit.
But: A vehicle parked on a public street is still on a road, and several jurisdictions word their rules as applying whether you are driving or stationary.
Fitted but switched off
Where the rule is about the light a vehicle shows rather than about what is fitted to it, an installation that is switched off is a different question from a lit one.
But: This does not apply everywhere, and it is left off the jurisdictions where the rule prohibits fitting the lamp at all.
Where you mount it
Inside the cabin
ConditionalAllowed only if the light cannot be seen by other motorists through the glass, and never flashing.
The condition is visibility to other motorists rather than where the lamp is mounted, so a cabin strip can fail it through the windows. The prohibition on flashing applies wherever the lamp sits.
Engine bay
ConditionalAllowed only where the light cannot be seen by other road users — bonnet closed while driving, or the vehicle stationary.
Lighting here is hidden by a closed bonnet. Because the rules turn on what other road users can see, a bay light that cannot be seen while you drive is a different proposition from one showing through the grille or panel gaps. With the bonnet up at a show the vehicle is stationary and usually off a road anyway.
Ute tray or tub
ConditionalAllowed only as a work light: white, switched separately, and used while the vehicle is stationary.
Work lights are provided for by name: white, switched separately, and used only while the vehicle is stationary. Coloured tray lighting run while driving is not a work light and does not carry that permission.
On a trailer
ConditionalAllowed only if the lamps never flash and cannot be seen by other motorists. The trailer is registered and defected in its own right.
A trailer is its own registrable vehicle with its own required lamps, so it is inspected and defected separately from the car towing it. The same rule about lamps that are not permitted applies to it, and added lighting must not reduce the effectiveness of the trailer's tail lamps, indicators or reflectors.
What you must not do here
- Anything imitating a regulated lamp — a rain light, brake light, indicator, hazard or emergency warning lamp. Those are approved units doing a defined job, and a copy that looks right is worse than one that looks wrong, because other drivers act on it.
- Anything that flashes. Flashing lamps are prohibited by the Road Traffic Code 2000 other than indicators and emergency warning lamps.
- Audio-reactive modes. Lamps wired to flash in sympathy with a sound system are named specifically as not permitted.
- Any configuration visible to another motorist, moving or parked — including light reflected off chromed underbody components.
- Colours or patterns that could be confused with turn indicators, brake lamps or emergency warning lamps.
- Anything that reduces the conspicuity of the vehicle's statutory lamps.
Under-body lamps are accepted in Western Australia provided they do not flash and are not visible to other motorists, whether the vehicle is moving or parked. That visibility condition is strict: a driver in a low car being able to see the lamps is grounds for a defect notice on its own, as is light reflecting off chromed underbody components.
The legislation
- Information Bulletin IB-108B — Under-Body Lighting and other Decorative Illumination (WA Department of Transport and Major Infrastructure), Under-body lamps; Prohibition on flashing lamps
Accepts under-body lamps subject to conditions, and prohibits any flashing including audio-reactive modes.
Generally these under-body lamps will be acceptable providing the lights themselves do not flash, and are not visible to other motorists, either when the vehicle is driven or stationary.
WA Department of Transport and Major Infrastructure, Information Bulletin IB-108B, last updated 10 May 2025.
- Road Traffic Code 2000 (WA), provision not yet identified
Prohibits flashing lamps other than turn signal indicators and emergency vehicle warning lamps.
Last checked 16 August 2026.
A starting point, not legal advice. Road rules change, and an officer at the roadside is not bound by what we have written here. Where we cite legislation, follow the link and read it — that is the thing that governs you, not our summary of it.
