Yesterday, my I was in my friends Cadillac Escalade ESV (the extra big one). He was making a left at a double turn lane. The small Pontiac in the inside turn lane almost drifted into his gigantic boat of an SUV and would have side swiped us if my buddy hadn't made an extra wide turn. There is no way he couldn't have seen the Caddy; it must have looked like a giant black and chrome wall from his perspective. I ride down a long curvy road that goes a good mile or so without any stop signs; 35mph speed limit. On a few occasions I've seen cars flying down that sucker at ~80mph, basically treating it like some sort of race track to test their car's performance. That's just how people are. To some extent I can't blame them; I guess if you're going to pay $40, $50, $60k or more for a high performance car, then you're going to want to see how it performs.
Moral of the story: (some) people just don't pay attention or give a flying a **** when they're driving and there is no way in the world to avoid all these people if/when we dare venture out on the roads. FYI, your chances of dying in a traffic fatality in your lifetime are ~1 in 75 (I've seen the calculation spit out ~50 - 100 and I guess that number must shoot up significantly for cyclist who dare venture onto the roads. Yeah, it's scary out there.