...forget the bike riders...its amazing how stupid some motorists appear to be when you ride a bike...Ive been hit from behind,swerved at,yelled at had objects thrown at me from cars NOT because i was holding them up...just simply for being on a bike.
Speaking as someone who had a car deliberatley clip them from behind at an intersection while waiting for the lights to turn green(I caught up with him at the next set...lets just say he needed a new side mirror

)...maybe they run red lights to put as much distance between themselves and the cars.
Bike lanes mysteriously seem to disappear at major intersections...just when you need them most!