Sometimes while driving a car long distance I will kind of "awaken", not that I was sleeping, but suddenly become "aware" and wonder what happened to the time after when I last recalled where I was. I look around to see that I am on course / schedule and wonder if there had been any risk during the missed time. This hasn't happened recently but I know this has happened to other people. White Line Fever I think it is called. (not the movie)

http://www.gadling.com/2012/08/31/hi...w-to-avoid-it/

exerpt:
"Highway hypnosis is a trance-like mental state brought on by the monotony of the road. In other words, you're zoning out, and while one part of your brain is still able to operate your car, the other half is in la la land. If you've ever driven a stretch of highway and have no memory of it, you've had white line fever, baby. The important thing to take away from this is that it's nearly as dangerous as nodding off at the wheel."