Most of the articles i've read appear to say that the majority of bike accidents these days are single vehicle accidents, typically the rider loosing control on a left hand bend and drifting into oncoming traffic.
Thats certainly what i have noticed as i've been out and about. I cant think of a single bike accident that i've seen recently that has involved another vehicle. I'm not saying that they dont happen, of course they do.
I live in an area thats popular with bikes so we tend to get more than our fair share of incidents.