A new study of driver attitudes toward bikers shows that being able to perceive cyclists is influenced by driver attitudes toward cyclists. Those who don't like or don't care about cyclists don't see them even when looking at them. They also found that the social dominance of vehicles means they have a far higher degree of lethality over "alternative" transportation like biking or walking:
Roadways are highly congested (and thus contested), publicly funded space, and both space and funding are a finite and limited resource. This results in the perception and reality of roadway competition as a zero-sum game between roadway users (Aldred, 2012). It may be that this "realistic" competition is a stand-in for social competition; that is, the roadway is a battle ground for social domination, rather than just access to physical space.
Here's a classic example:
Lots of other great info in there, like how nicer cars are more likely to hit bikes, and the dangers of crossing the street while black. (In B4 b-b-bikers wanna take away muh carz!)