1. You can't stop yawning.
2. You feel restless or irritable.
3. Your mind wanders or you have disconnected thoughts.
4. You have trouble keeping your eyes open and focused, especially at stoplights.
5. You can't remember driving the past few miles.
6. Your driving becomes sloppy (tailgating, weaving, missing traffic signals).
7. You have trouble keeping your head up.
8. You hit the rumble strips along the side of the road.