Two disclaimers here:
1) I do a fair bit of road biking, but not as a commuter.
2) I'm one half of an ambulance crew in and around Manchester.
Over the last couple of weeks, me and my oppo did an unscientific survey on cyclists. We look first of all at cyclists before 0800 and after 1500 (which in Manchester is generally pretty dark and grim). We categorized cyclists according to their lighting...none, crap, decent, excellent.
After 7 long, 12 hours shifts we have the following figures:
None: 24%
Crap: 29%
Decent: 17%
Excellent: 30%
"Crap" means they have lights but until you're almost on them you can't see them (often these lights are obscured by clothing/rucksacks or are clearly shitty cheap lights) Helemt usage was over 70%.
Given that we were actively looking out for them some were practically invisible. The best one was a black guy, on a black bike, wearing black clothes with his kid on the back, in rush hour. No lights, no helmets: awesome.
The third disclaimer is that over the last 2 weeks we've been to 3 car vs cyclist call outs all of which have been pretty traumatic (in the medical sense of the word) - none had lights that we could see.
Are you visible? How much have you spent on lights? (I've spent about £200). being seen from the front and rear is great, but think about the side view too. 98% of cyclists don't have any sideways visible lighting (on arms, legs or spokes)
I present these figures for discussion, but it seems to me that 70% of cyclists are their own worst enemies.
Post edited at 19:34