Safe Speed Forums

I would say using both a fixed and blinking light would give the best result; high quality, bright, fixed lights and a pair of cheap blinking ones possibly.

They are not legal for road use but I doubt if anyone has been prosecuted for using them.

not legal under what law ?

Lighting Regulations

Abbreviated to RVLR: the Road Vehicle Lighting Regulations 1989 (amended in 1994 and 2005) require pedal cycles to have various lights and reflectors fitted, clean and working properly, when being ridden on a public road between sunset and sunrise. Cyclists may also be required to light up in conditions of seriously reduced visibility during the day, but only if they have functional lights already fitted. Lights are not required when the cycle is stationary or being pushed along the roadside.

It has to be said that the fine details of RVLR are seldom enforced; and provided you show some kind of white light in front and red behind you are unlikely to be challenged. If you are involved in a night-time accident however, any slight illegality with respect to your lights or reflectors may be regarded as contributory negligence. The following items are the minimum required, on a bicycle or tricycle, in order to ride it legally at night:
Front Lamp

One is required, showing a white light, positioned centrally or offside, up to 1500mm from the ground, aligned towards and visible from the front. If capable of emitting a steady light it must be marked as conforming to BS6102/3 or an equivalent EC standard. If capable of emitting only a flashing light, it must emit at least 4 candela.
Rear Lamp

One is required, to show a red light, positioned centrally or offside, between 350mm and 1500mm from the ground, at or near the rear, aligned towards and visible from behind. If capable of emitting a steady light it must be marked as conforming to BS3648, or BS6102/3, or an equivalent EC standard. If capable of emitting only a flashing light, it must emit at least 4 candela.
Rear Reflector

One is required, coloured red, marked BS6102/2 (or equivalent), positioned centrally or offside, between 350mm and 900mm from the ground, at or near the rear, aligned towards and visible from behind.
Pedal Reflectors

Four are required, coloured amber and marked BS6102/2 (or equivalent), positioned so that one is plainly visible to the front and another to the rear of each pedal.
Exceptions and explanations

Age brings privileges. To name but two: 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.
Cycle trailers need a rear lamp and reflector; sidecars also need a front lamp.

The Euro-friendly clause

Thanks to a European Directive of a few years ago, wherever a British Standard (BS) is referred to, equivalent standards from other EC countries must now also be recognised, but only if they provide an equivalent level of safety etc. It’s not exactly clear which do. However Germany has arguably the strictest cycle lighting laws in Europe so we consider it safe to use equipment that is marked accordingly, with a “K~number”.

It should also be noted that wherever a British Standard is referred to, that reference applies to a specific edition. In the case of BS6102/3, that is the 1986 edition, as amended on 15th April 1995 and again on 1st September 2003. These amendments removed the filament bulb design restrictions, so that lamps may now get their light from LEDs – or indeed anything else!
Dynamos

Dynamo powered lights are legal even though they go out when you stop. That’s allowed so long as you stop on the left. Usually it’s much safer to stay where you are (e.g. in a stationary queue with left-turning traffic filtering up your inside), since most cars do stop for red traffic lights and those that don’t are unlikely to pay more heed to a bike lamp! Nevertheless: dynamos and lamps are now available with reliable back-up (standlight) features that either keep them on or light up a diode instead of the bulb.
Additional lamps and reflectors

Some cyclists like to fit extra lamps and reflectors, in addition to the approved ones, specified above. This is perfectly legal provided they are the correct colour and in an appropriate position. These optional lamps and reflectors do not have to comply with any standards, but it’s illegal to use some designs of lamp or reflector that have specific other uses. You must not, for instance, show a red light at the front, or a white light to the rear, or fit triangular-shaped rear reflectors on anything except a trailer.

The Pedal Cycles (Safety) Regulations (PCSR) ensure that every new bicycle is sold with several extra reflectors, not required by RVLR, but (strangely) does nothing at all to facilitate the fitment of front and rear lamps. These additional reflectors are found on the sides of the wheels, clear white or coloured yellow, and there's also a "white" reflector on the front of the bike. You are at liberty to remove the surplus side and front reflectors, which in any case are of dubious benefit, but be sure to fit the necessary front and rear lamps.
Flashers

Thanks to the enactment of Statutory Instrument 2005 No. 2559: on 23rd October 2005, it finally became legal to have a flashing light on a pedal cycle. Even better: it became possible for a flashing light to be approved, meaning no other light would be needed in that position. And since BS6102/3 does not yet cater for flashing (but is likely to be amended to do so quite soon), approval is for the time being, granted simply on the basis of brightness.

Because DfT very much prefer anything that possibly can be evaluated against a proper technical standard, so to be evaluated: any flashing lamp that is also capable of emitting a steady light is approved only if it conforms with BS6102/3 when switched to steady mode. Since most (probably all) flashing lights do also have a steady mode, and since none of their manufacturers can be bothered to test and mark them to the pernickety standards of one small country on the fringes of Europe, it's unlikely that any flashing light actually qualifies for approval. But since it became theoretically legal to ride a bike with only flashing lights on it, the Police are nowadays no more likely to quibble its legal status than one equipped with steady lights – unless they're rather dim or involved in an accident of course.

If you'd like to read the Department for Transport's explanation, see this page on their website.

Road Vehicle Lighting Regulations 1989 (amended in 1994 and 2005) as explained at
http://www.dft.gov.uk/pgr/roads/vehicles/vssafety/guidanceaboutlightsonpedalbi4556

The lighting I mentioned post dates BS 6102-2 and thus falls under paragraph 10. It would be illegal on the first bullet point ("It must not dazzle other road users")

I have a flashing light on helmet

Which is outwith the RVLR which only apply to lights firmly attached to the bicycle. You are legally allowed to decorate your body with lights like the Rhinestone Cowboy

Are people with that level of photo sensitive epilepsy allowed to drive?

And if they are should we revert to hand signals or semaphore indicators; remove the flashing yellow phase from pedestrian crossings; remove the flashing red lights at railway crossings; put fixed blue lights on emergency vehicles?

No because those are needed whereas cyclist are selfish little pr@ts with no concern beyond their own safety.

Ride out after sunset and it becomes apparent that a cyclist is less visible to other road users. Driving a car and seeing an ill lit cyclist doest rather drive a meassage home to these road users

No because those are needed whereas cyclist are selfish little pr@ts with no concern beyond their own safety.