A view obstruction not mentioned in this thread so far is the A-pillar blind spot. An "A pillar" is a car's front roof support. Since today's cars use them for rollover protection, they can be quite substantial--unlike the stylish, pencil-thin posts on a
1962 Chevrolet 409 "bubble top", for example. Next time you're in your car at a stop, move your head around to get an idea of what that structure can block: a pedestrian, bicyclist, motorcyclist, and maybe even a car.
This came to mind today watching the latest DanDanTheFireman video (thx to Budman for bringing him to my attention):
[youtube]OL8HUu4XrB8[/youtube]
As the white car turns left--a point when the SUV driver should be checking for more traffic--notice that the right A-pillar is directly between the motorcycle and the driver.
Even without the A-pillar factor, situational awareness would trigger elevated attention here; a car attempting to enter your path of travel is always a concern. So, this is just an additional wrinkle that helps predict incursions.
A good countermeasure--but only when far enough out that it wouldn't interfere with a potential emergency maneuver--is the SMIDSY weave (see
post #64 of this thread). If you are in the pillar's visual shadow, lateral movement could bring you out of it. Of course, you still cannot count on being seen. Expect an incursion and slow to a speed that will make it easier to avoid--as the rider in the video did.
When I first read about the A-pillar blind spot, I adopted a habit that is still with me: In my car, when checking for cross traffic, I move my head from side to side to see around the pillar.