why do some people become sleepy while driving?

sleepiness when driving is dangerous, that is why when i feel sleepy while driving, i stop for a while, go out from the car and shake my whole body to wake it up. make sure dont listening to soft music while driving.

sometimes they become sleepy while driving maybe they take a medicine that the effect is diziness, i think this is one of the reason why some drivers become sleepy while driving...

I always become sleepy when driving or listening to lecture. I can't control it. When I'm driving, I tend to sing and dance to keep myself awake. Is there any way to cure this sleepiness. By the way, what is narcolepsy??

Hey mayank, i dont feel sleep while driving.. but feel sleepy when someone else is driving // like is train.. travelling bus. thanks and enjoy :)

My mom becomes sleepy while driving. She got into accidents too, I think twice now. One with a police man. Good thing she didnt get into far more serious accidents. Well, I think it's not narcolepsy. Because she is a very busy person. Seriously. Add she does not get full 8 hours of sleep. That is why she gets sleepy.

its a disease i think!