Bloody hell, I saw this happen in my rear-view on the way to work this morning. Scary. http://bit.ly/514Wwe
It's all a bit unnerving, really. One car suddenly changed direction, crossed from the inside lane and t-boned a car coming down the on ramp. That car ended up travelling across oncoming traffic and got clipped by a truck.

Was probably 6 car lengths or so behind me, something like that... most unsettling.
It might be somewhat detrimental to the fuel efficiency, it must be said. :)
Holy Cow dude. Good job you didn't leave 20s later...
Random chance is random, but it still gives you the willies when you see it that close by...