No one can deny that driving drowsy or asleep is extremely dangerous, it may happen to a lot of people, including drivers who didn't get enough sleep, shift workers, drivers who use medications that make them sleepy and of course drinking, all these combined represent a dangerous situation that we can easily avoid. In 2013 The National Highway Traffic Safety Administration estimates that drowsy driving was responsible for 72,000 crashes, 44,000 injuries, and 800 deaths in 2013 [1].

Thats were we can help, people know these and accidents still happen, so I propose a Brain Computer Interface that monitor our brain consciousness more specific the Alpha and Theta waves, these waves are the ones that told us if our brain is relaxing deeply or day dreaming with your eyes closed and the transition between these states is were we fall asleep.

References: 

[1] National Highway Traffic Safety Administration. Research on Drowsy Driving. Accessed October 20, 2015.