Bike light laws in the UK: what you need to know

Flashing or steady lights? How bright is too bright? We explain all

There's a lot of confusion surrounding the law for bike lights in the UK. Is flashing OK, or do they have to be steady? And do you have to fit reflectors too? Here, we set the facts straight. 

It's worth explaining why we need to fit and use lights at night in the first place — it's not just to see where we're going; if you're riding on city streets then street lights probably do that for you fairly well. Equally important is that bike lights and reflectors help us to be seen by other road users.

If you're looking for advice on which bike lights to buy, check out our guide to the best bike lights for road cycling.

The current UK legislation on bike lights

When riding at night in the city, street lamps will help show the way — but they're not enough to help other road users spot you
When riding at night in the city, street lamps will help show the way — but they're not enough to help other road users spot you

According to the Road Vehicles Lighting Regulations (RVLR), it's illegal to cycle on a public road after dark without lights and reflectors. There have been quite a few changes to this legislation in recent years: the current version of the RVLR was published in 1989, and has since been amended multiple times, most recently in 2009.

To avoid major trouble with the law (and to stay safe), a white light must be showing from the front of your bike and a red light from the rear. The RVLR specifies minimum outputs for these lights and requires cyclists to fit reflectors too, so if you lack either of these things and are involved in a night time accident then it could be regarded as contributory negligence. But you’re unlikely to be pulled over by the police as long as the front and rear of your bike are illuminated.

This is backed up by Rule 60 of the Highway Code, which says:

"At night your cycle MUST have white front and red rear lights lit. It MUST also be fitted with a red rear reflector (and amber pedal reflectors, if manufactured after 1/10/85). White front reflectors and spoke reflectors will also help you to be seen. Flashing lights are permitted but it is recommended that cyclists who are riding in areas without street lighting use a steady front lamp."

Is there a maximum output limit for bike lights?

The most powerful lights can brightly illuminate a dark path, but also have the potential to dazzle other road users
The most powerful lights can brightly illuminate a dark path, but also have the potential to dazzle other road users

No there isn’t, but you don’t want to dazzle oncoming drivers, for obvious reasons! 

Bike light technology has improved in leaps and bounds since the introduction of LED lights, and they now run brighter, for longer, and weigh less than old dynamo powered lamps.

“If your lights cause undue dazzle or discomfort to other road users, then you're breaking the law and the police are within their rights to fine you," says Cycling UK. In practice, though, as long as your bike has a front white and red rear light it’s rare to be stopped and fined by the police, but please be considerate to other road users.

One more word of advice — don't mount your most powerful front light on your helmet. It completely dazzles oncoming road users, and is very inconsiderate.

The minimum equipment required for riding a bike at night

  • A front lamp showing a white light, positioned up to 150cm from the ground and facing forwards. If capable of emitting only a flashing light, it must emit at least four candela (a unit of light intensity, comfortably exceeded by modern lights)
  • A rear lamp showing a red light, positioned between 35cm and 150cm from the ground, facing rearwards. If capable of emitting only a flashing light, it must emit at least four candela
  • Rear reflector, coloured red, positioned between 25cm and 90cm from the ground, facing rearwards
  • Pedal reflectors, coloured amber, positioned so that one is plainly visible to the front and another to the rear of each pedal

Can I fit only flashing lights?

Yes, you can use only flashing lights front and rear, as long as they are both capable of emitting at least four candela (a unit of light intensity, comfortably exceeded by modern lights), and provided it flashes between 60 and 240 times per minute (1–4Hz). The jury is still out on whether it’s safer to run flashing or steady lights, so the safest thing to do is run both, perhaps using a helmet-mounted light for the rear flashing LED.

Also, be aware that it’s illegal (not to mention highly dangerous) to show a red light at the front, or a white light to the rear, or fit triangular-shaped rear reflectors on anything other than a trailer. This could easily confuse drivers, especially in poor weather conditions.

Do my lights have to comply with UK standards to be legal?

Most lights sold in the UK by reputable dealers comply to the relevant safety standards
Most lights sold in the UK by reputable dealers comply to the relevant safety standards

Yes — but we can assume that modern manufactured products sold by reputable dealers in the UK will comply with these standards.

If however you bought your lights online at a surprisingly low price from an overseas seller, don't be surprised if they don't comply. And be aware that if you're involved in a night time accident then this could be regarded as contributory negligence.

Can I use dynamos instead?

Dynamo-powered lights are legal even though they stop emitting light when you stop. It’s fine from a legal standpoint so long as you stop on the left. 

Many modern dynamos actually come with something called a standlight, which provides a limited amount of extra stored power even when the dynamo isn’t running.

Do I have to use lights in daytime low visibility conditions, such as fog?

The minimum equipment for riding a bike at night in the UK includes a front light (white), a rear light (red), and reflectors
The minimum equipment for riding a bike at night in the UK includes a front light (white), a rear light (red), and reflectors

Unlike other vehicles, bicycles are not required to have lights fitted and switched on during conditions of seriously reduced visibility — because lights are not required to be fitted during daylight hours.

However, it is a very sensible idea to have them fitted and switched on if you hit a bank of fog, so keep a close eye on that weather forecast.

Are older bikes exempt from these laws?

Not exactly. Cycles manufactured before October 1990 can have any kind of white front lamp that is visible from a reasonable distance, and pre-October 1985 cycles don’t need pedal reflectors.

Can I remove the wheel reflectors that my bike came with?

Yes you may, though it will make your bike less visible at night. 

The Pedal Cycles Safety Regulations (PCSR) apply to the sale of new bikes in the UK, and state that every new bicycle sold must come with several extra reflectors beyond those mentioned above. However, they're not required by the Road Vehicles Lighting Regulations to be fitted, so can be considered a 'bonus'.

These additional ones include reflectors on the sides of the wheels (clear white or coloured yellow), and a clear white reflector on the front of the bike. Feel free to remove the front and side reflectors if you want, but be aware that the bike shop you bought it from is probably unwilling to do it for you.

Jamie Beach

Deputy Editor, UK
Jamie's been addicted to bikes from the moment his stabilisers came off. Earliest cycling memory is the chipboard-ramp-on-bricks, but happiest one is bombing down a Mallorcan mountain pass that seemed it might never end. Always on the hunt for the perfect rain jacket, a keen collector of hats.
  • Discipline: Road, gravel
  • Preferred Terrain: Big mountains with long climbs, equally long and fast descents, the chance to get above the treeline.
  • Current Bikes: Genesis Croix de Fer, Brompton M3L
  • Dream Bike: BMC TeamMachine SLR01, Moots Routt
  • Beer of Choice: Augustiner
  • Location: Bath, Somerset, UK

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