This article was published in 2009, in Newsletter 82.
I believe (but admit to having no hard evidence) that Heather Coleman is wrong in saying that the only other road users that unlit cyclists put at risk are other cyclists. I believe that there is also a significant risk to motorcyclists – if a motorcyclist hits an unlit cyclist it seems to me that there is a reasonable risk that the motorcyclist will also be killed, which is clearly Not Fair.
I gave up driving a bike some years ago, but I remember that the most invisible obstructions on the road were unlit cyclists, especially when it is raining. And as a motorcyclist can’t see a bicycle’s lights from the side, get wheel reflectors if you don’t want to be hit by a motorcycle when you’re cycling round a roundabout.