I have one more thing I want to say, and that is this: if you're REALLY concerned about safety, get, and use, a bicycle mirror. I know they're a pain (they ARE; I won't deny or minimize that). But as I said in my mirror post, over a year ago:
I believe in bicycle mirrors. By the time your helmet comes into play, it's too late: something drastic has already happened. My contention is that bicycle helmets really protect everybody else: riding clubs, schools, municipalities; they either can say that the helmet saved you, or they can tut-tut if you get into an accident and you weren't be-helmeted. But the mirror, once you've gotten used to it, and you know its limitations (and it both requires getting used to, and has limitations), saves you from getting into the accident in the first place. If helmets protect everybody else, mirrors protect you. I can say with certainty that my bike mirror has saved my life at least twice.The worst accident I ever saw between two cyclists probably would have been avoided if one had been using a mirror. And I stick to my claim that the mirror has saved my life at least twice. You are undoubtedly safer wearing both a mirror and a helmet. But if you're only going to use one, use the mirror.