Where I live, nearly all cyclists are the kind of people who do it because they can't afford a car. (Not that there's anything wrong with that). They tend to move a lot slower than those of us who do it for the exercise or just prefer it to driving. I think drivers are conditioned to cyclists moving at 5 or 6 mph, and sometimes they think they have more time than they really do to make their move. Of course, it's their responsibility to observe and accurately judge the speed of others on the road, but some prefer to drive "unencumbered by the thought process."
I don't know what you can really do other than be very visible and very vigilant.
Jim