Road safety and visibility
This article answers the question: why do tractors have flashing amber lights.
A tractor’s flashing amber light is a warning beacon that signals caution to other road users.
Jump to
Treat the beacon as a “slow hazard” cue for other drivers.
Meaning
A flashing amber beacon means a vehicle presents a potential hazard because it moves slowly, stops often, runs wide, or carries an abnormal load.
You use the beacon to increase conspicuity, so drivers spot you earlier and adjust their approach.
The beacon reduces surprise, which reduces late braking and poor overtakes.
A car at 60 mph closes on a 20–25 mph tractor fast.
Drivers misjudge that closing speed on bends, crests, and in rain.
An amber beacon creates an early “slow hazard” cue that headlamps alone do not always create.
A tractor plus implement can exceed a car lane width in seconds.
Mudguards, loaders, mowers, hedge cutters, and wrapped bales change your working width and rear overhang.
The beacon warns drivers to avoid tight passes and late squeezes.
A tractor turns slower and needs more road to swing in and out.
You often sit partly in the lane while you line up gates and field entrances.
The beacon signals caution before other drivers see your indicator or trailer angle.
Rain spray, fog, dusk, and glare reduce contrast against hedges and dark cabs.
Mud on lenses reduces light output and makes signals hard to read.
The beacon provides a bright, high mounting point that cuts through clutter.
Treat this as practical guidance, and check GOV.UK for edge cases.
Key rule
UK guidance links amber beacon use to unrestricted dual carriageways for slow vehicles.
The Highway Code states that vehicles with a maximum speed of 25 mph or less, such as tractors, must use a flashing amber beacon on unrestricted dual carriageways.
That requirement comes from the Road Vehicles Lighting Regulations 1989.
Practical note
Treat this article as practical guidance, and always check the current GOV.UK wording for edge cases.
Keep your road lights correct, and avoid glare that hides brake lamps and indicators.
Use it early, and keep it on until you clear the risky section.
Principle
Use the beacon when you create a credible “unexpected hazard” for following traffic.
Use it early, and keep it on until you clear the risky section.
Unrestricted dual carriageways
If your tractor’s maximum speed sits at 25 mph or less, treat the beacon as mandatory on unrestricted dual carriageways.
That rule exists because fast traffic closes on slow vehicles with little warning time.
Use indicators for intent, and use the beacon for presence and caution.
Amber beacon
An amber beacon warns of your vehicle as a hazard because of speed, size, or load.
The beacon signals caution around a slow or unusual vehicle.
Hazard lights
Hazard lights warn of a temporary stop or immediate danger, not “slow moving by default”.
Use hazards when you stop in a risky position or when you must warn of an immediate obstruction.
Rule of thumb
Use indicators for intent, and use the beacon for presence and caution.
Most mistakes reduce meaning, reduce visibility, or create glare.
You forget the beacon on, and drivers stop treating it as meaningful.
You fit a cheap unidirectional amber strobe that does not give true 360-degree warning.
You mount the beacon too low, and trailers or loads block it from behind.
You run a bright rear work light on-road and cause glare that hides brake lights.
You tow with dirty lenses, weak earths, and intermittent trailer plugs.
You rely on one light source when the load blocks it at angles.
Prioritise reliability, 360-degree coverage, and proper mounting over raw brightness.
Buying principle
Pick a beacon that drivers can see clearly from distance, in rain, and through spray.
Prioritise reliability, 360-degree coverage, and proper mounting over raw brightness.
Shop amber beaconsCompliance and visibility
Aim for 360-degree visibility around the vehicle and the load.
If the load blocks the beacon from some angles, add a second beacon or reposition it.
Avoid unidirectional amber lamps for on-road warning use.
LED beacons start fast and hold output under vibration.
Halogen rotating beacons still work, but they need more maintenance and draw more power.
Choose LED for daily road moves and winter work where grime and vibration hit hardest.
Magnetic mount suits occasional use and shared machines, but cables snag on doors and mirrors.
Permanent mount suits frequent road travel and reduces the risk of loss and water ingress.
Match voltage and connector type to the tractor and any auxiliary switch panel.
Check cable routing and fuse protection, and avoid loose cigar plugs if you bounce on lanes.
Mount it high, and keep it clear of loaders, tanks, and high loads.
Add a second beacon if the load blocks sight from behind or from the offside.
Treat lighting as part of safe transport, not just a compliance tick box.
Run the beacon with clean, working headlamps, tail lamps, brake lamps, and indicators.
Keep reflectors intact and visible, especially on trailers and trailed kit.
Add higher-mounted rear indicators and brake lamps on trailers if following traffic often misses them.
Treat lighting as part of safe transport, not just a compliance tick box.
This takes two minutes and prevents most visibility failures.
Checklist
Next step
If you cannot guarantee 360-degree visibility, add a second beacon or change the mounting point.
Shop amber beacons Back to topShort answers that match real road questions.
UK guidance states tractors with a maximum speed of 25 mph or less must use a flashing amber beacon on unrestricted dual carriageways.
Turn it on when your tractor creates a hazard through slow speed, width, load, or manoeuvres, and keep it on until the hazard ends.
An amber beacon signals caution around a slow or unusual vehicle.
Hazard lights signal a temporary stop or immediate danger.
You can use a beacon to improve conspicuity, but you still need correct road lighting and you must avoid glare and confusion.
Two beacons help when a load, cab, or implement blocks 360-degree visibility from one mounting point.
Buy a 360-degree amber warning beacon, mount it high, and choose a robust LED unit if you travel on roads often.
Need help choosing
Tell us your tractor voltage, your mount type, and whether you tow wide kit.
Shop tractor beaconsUse this as your closing paragraph and snippet.
Tractors have flashing amber lights because they need a clear warning signal that they present a slow moving or unusual road hazard.
The beacon gives drivers earlier recognition time, which reduces harsh braking and risky overtakes.
Use the beacon with clean, working road lights, and choose a true 360-degree unit mounted where the load cannot block it.
