The numbers
- Lights required
- Sunset to sunrise, and any time visibility drops below 150 mRegulation 157(1)(b)
- Motorcycle headlamp
- Lit at all times, day and nightRegulation 157(2)
- Main beam must show a person or vehicle at
- At least 100 m aheadRegulation 160(a)
- Dip your lights when
- Main beam would dazzle oncoming trafficRegulation 157(3)
- Driving on parking lamps only
- A separate offenceRegulation 165(2)
The 150-metre test decides it, not the clock alone
Regulation 157(1)(b) requires your head lamps, rear lamps and number-plate lamps to be lit between sunset and sunrise — but it doesn't stop there. It also requires them lit "at any other time when, due to insufficient light or unfavourable weather conditions, persons and vehicles upon the public road are not clearly discernible at a distance of 150 metres".
That second half is what makes this a night-driving rule and a poor-visibility rule at once. Heavy rain or thick mist at three in the afternoon can fail the 150-metre test just as completely as ten at night can, and the duty to switch your lights on is the same either way.
A motorcycle's headlamp is not a night-only light
Regulation 157(2) requires a motorcycle, motorcycle with sidecar, motor tricycle or motor quadrucycle to have its headlamp lit at all times — including broad daylight. It's one of the clearer differences between a car's lighting duty and a motorcycle's: a car only needs its headlamps on when 157(1)(b) is triggered, but a motorcycle's is a permanent requirement, because a single-track vehicle is far easier for other drivers to miss.
The one exception is narrow and mostly historical: a machine built before 31 December 1960, used only between sunrise and sunset.
Main beam, dipped beam, and dazzling the other driver
Regulation 160(a) sets what main beam is for: it must be capable of showing a person, vehicle or substantial object at least 100 metres ahead. That's the reach you're relying on for reaction time on an unlit road.
Regulation 157(3) sets the limit on it: you must extinguish the main beam if it could cause a dangerous glare to oncoming traffic. In practice that means dipping well before you meet an oncoming vehicle, not at the last moment — the other driver's 100 metres of forward vision is worth as much as yours.
The mistake
Driving with only parking lamps on because it feels like "enough light to be seen". Regulation 165(2) makes this its own offence — a vehicle in motion may not be lit by its parking lamps alone, whatever the driver's judgement of visibility.
The other one is treating a motorcycle's daytime headlamp as optional because it's already light outside. Regulation 157(2) doesn't distinguish day from night for a motorcycle at all.
Lighting rules sit in the rules of the road section
They're scored with the rest of the rules section, separately from signs and vehicle controls. The free readiness test takes a couple of minutes and shows you the three sections apart.
Take the free readiness testCommon questions
When must I switch my headlights on?
Between sunset and sunrise, and at any other time when poor light or bad weather means people and vehicles on the road aren't clearly visible from 150 metres. Regulation 157(1)(b) covers both.
Do motorcycles need their headlight on during the day?
Yes. Regulation 157(2) requires a motorcycle's headlamp to be lit at all times, with a narrow exception for machines built before 31 December 1960 that are only used between sunrise and sunset.
How far should my headlights let me see at night?
Main beam must be capable of showing a person, vehicle or substantial object at least 100 metres ahead, under regulation 160(a).
Is it illegal to drive with only your parking lights on?
Yes. Regulation 165(2) makes it a separate offence to operate a vehicle in motion with only the parking lamps lit.
When should I dip my headlights?
Before your main beam could cause a dangerous glare to oncoming traffic, under regulation 157(3) — in practice, well before you actually meet the other vehicle, not at the last second.
Sources
- National Road Traffic Regulations, 2000 — regulation 157"Vehicles to be equipped with certain lamps and times when certain lamps to be lighted". Subregulation (1)(b): head lamps, rear lamps and number-plate lamps shall be kept lighted between sunset and sunrise, and at any other time when, due to insufficient light or unfavourable weather conditions, persons and vehicles on the public road are not clearly discernible at a distance of 150 metres. Subregulation (2): a motorcycle, motorcycle with sidecar, motor tricycle or motor quadrucycle shall have its headlamp lighted at all times, except a machine manufactured before 31 December 1960 used only between sunrise and sunset. Subregulation (3): the driver shall extinguish the main-beam if it could cause a dangerous glare to oncoming traffic.
- National Road Traffic Regulations, 2000 — regulation 160(a)Every head lamp emitting a main-beam shall be adjusted and maintained so as to be capable of adequately illuminating an area ahead enabling the driver to see a person, vehicle or substantial object at a distance of at least 100 metres.
- National Road Traffic Regulations, 2000 — regulation 165(2)No person shall operate on a public road a motor vehicle of which only the parking lamps are lighted while the vehicle is in motion.
Last updated 2026-09-23.