In defense of drivers, I know that, when I am in a car and I approach a cyclist, it helps me drive a lot better if the cyclist makes eye contact and lets me know exactly what his intentions are. Otherwise, I have no idea if the cyclist knows what he is doing - or if I should be prepared for some sudden, stupid move. Where there's uncertainty on the part of either the driver of the cyclist, there's greater potential for disaster.
I hate to admit it, but the majority of cyclists I come across on the roads of Long Island do not ride responsibly. In a world in which drivers distracted by phone calls and text messages are capable of paying 50% attention to the road, at best, this is a pretty big gamble on the cyclists' part.