There is one, admittedly relatively small, study which indicates that the triangular set up of auxiliary lights and main headlight is more conspicuous than a single light. But how far, ie bright, can you go when it comes to legally lighting up?

“a light which causes ‘undue dazzle’ is illegal”

Auxiliary lights make you appear bigger and wider which is legal, but a light which causes ‘undue dazzle’ is illegal. The test is not numerical, ie wattage or lumens, it is about the angle and brightness of your light and whether your foglight, headlight or brake light causes undue dazzle. Which means massive off-road style Baja lamps are likely to be illegal, while correctly set but powerful lights are unlikely to get you into trouble.

The human eye is drawn to movement, or changes of light, which would reasonably lead you to think that a police bike displaying powerfully strobing blue lights is next to impossible to miss. However, all motorcycle coppers and blood runners have stories about cars pulling out on them.

Crucially the use of flashing lights attached to regular bikes ridden by regular riders is illegal, yet flashing lights attached to clothing are legal. A belt, helmet or a jacket with LED lights is legal, and they can flash too.

If you want to rock the Christmas tree look, you will have the twin benefits of moving lights, and the lights potentially making out a human shape, another thing which the human eye is drawn to. You might not look uber cool, but you can flash without breaking the law.

“the test is do the lights ‘automatically flash’?”

It is possible to buy lights which flash and can easily be wired into a motorcycle but, as mentioned before, these are not legal. However, the test is do the lights ‘automatically flash’? The only lights on a motorcycle which can automatically flash are the indicators.

When interpreting statutes words are given their ordinary and natural meaning, so a flash would be a sudden and short burst of light. Auxiliary lights which do not dazzle nor flash, but glint, by use of fast modulation are, in my opinion, wholly within the law.

So, you can lawfully light yourself up on a motorcycle by the use of solid auxiliary lights, flashing lights not affixed to the bike but affixed to your clothing and finally by modulating lights which do not flash but appear to flicker.

“A strobe or flashing light will get you nicked”

Stretching your motorcycle lighting beyond these three additions to your standard lighting is likely to get you into trouble with the law. And despite the law being reasonably technical on this point any road traffic copper will know it. A strobe or flashing light will get you nicked. Piercing xenon lights may well be ignored as the test is a subjective one.

Andrew Dalton

Bike Magazine May 2017